Quarterly report pursuant to Section 13 or 15(d)

Stock-based Expense - Schedule of Stock-based Expense (Details)

v3.19.3
Stock-based Expense - Schedule of Stock-based Expense (Details) - $ / shares
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2019
Performance-Based Restricted Stock | Vesting Condition 1    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 11,300
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 60.84
Performance-Based Restricted Stock | Vesting Condition 2    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 105,733
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 69.50
Performance-Based Restricted Stock | Vesting Condition 3    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 11,300
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 66.92
Performance-Based Restricted Stock | Vesting Condition 4    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 105,733
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 77.84
Performance-Based Restricted Stock | Vesting Condition 5    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 11,300
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 73.01
Performance-Based Restricted Stock | Vesting Condition 6    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 105,733
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 88.96
Performance-Based Restricted Stock | Vesting Condition 7    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 3,184
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 78.44
Performance-Based Restricted Stock | Vesting Condition 8    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 11,300
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 85.17
Performance-Based Restricted Stock | Vesting Condition 9    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 105,733
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 100.08
Performance-Based Restricted Stock | Vesting Condition 10    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 3,184
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 87.85
Performance-Based Restricted Stock | Vesting Condition 11    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 3,184
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 100.40
Performance-Based Restricted Stock | Vesting Condition 12    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 3,198
Number of consecutive trading days required to calculate average price per share (in days)   20 days
Minimum price per common stock for vesting eligibility (in dollars per share)   $ 112.95
2010 Equity Incentive Plan | Restricted Stock | Vesting Condition 1    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 62,817 800,087
Vesting period (in years)   3 years
2010 Equity Incentive Plan | Restricted Stock | Vesting Condition 2    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 0 22,675
2010 Equity Incentive Plan | Restricted Stock | Vesting Condition 3    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted shares of restricted stock (in shares) 26,895
Vesting period (in years)   1 year