Quarterly report pursuant to Section 13 or 15(d)

Debt (Details)

v3.3.0.814
Debt (Details)
9 Months Ended
Sep. 30, 2015
USD ($)
Sep. 30, 2014
USD ($)
May. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Jun. 30, 2014
USD ($)
May. 31, 2014
USD ($)
May. 06, 2014
USD ($)
Line of Credit Facility [Line Items]              
Line of credit facility, additional borrowing capacity   $ 150,000,000.0          
Revolving credit facility $ 44,000,000     $ 20,000,000      
Unamortized debt issuance costs 1,100,000     $ 1,300,000      
Authorized amount of common stock repurchase     $ 50,000,000.0     $ 75,000,000.0 $ 50,000,000
Value of equipment in hands of employees, consultants, or customers         $ 2,500,000    
Aggregate permitted acquisition limit         150,000,000.0    
Additional borrowing capacity under certain conditions         $ 100,000,000.0    
Federal Funds Rate              
Line of Credit Facility [Line Items]              
Basis spread on interest rate   0.50%          
LIBOR              
Line of Credit Facility [Line Items]              
Basis spread on interest rate   1.00%          
LIBOR | Minimum              
Line of Credit Facility [Line Items]              
Basis spread on interest rate   2.00%          
LIBOR | Maximum              
Line of Credit Facility [Line Items]              
Basis spread on interest rate   2.50%          
Prime Rate | Minimum              
Line of Credit Facility [Line Items]              
Basis spread on interest rate   0.00%          
Prime Rate | Maximum              
Line of Credit Facility [Line Items]              
Basis spread on interest rate   0.25%          
Revolving Credit Facility              
Line of Credit Facility [Line Items]              
Line of credit facility, maximum borrowing capacity   $ 200,000,000.0          
Ratio of indebtedness   3.25          
Revolving line of credit facility, available borrowing capacity $ 156,000,000            
Revolving Credit Facility | Federal Funds Rate              
Line of Credit Facility [Line Items]              
Basis spread on interest rate 0.50%            
Revolving Credit Facility | LIBOR              
Line of Credit Facility [Line Items]              
Basis spread on interest rate 1.00%            
Revolving Credit Facility | LIBOR | Minimum              
Line of Credit Facility [Line Items]              
Basis spread on interest rate 1.25%            
Revolving Credit Facility | LIBOR | Maximum              
Line of Credit Facility [Line Items]              
Basis spread on interest rate 1.75%            
Revolving Credit Facility | Base Rate | Minimum              
Line of Credit Facility [Line Items]              
Basis spread on interest rate 0.25%            
Revolving Credit Facility | Base Rate | Maximum              
Line of Credit Facility [Line Items]              
Basis spread on interest rate 0.75%            
Letters of credit              
Line of Credit Facility [Line Items]              
Sub limit for issuance of letters of credit   $ 10,000,000.0          
Revolving line of credit facility, available borrowing capacity $ 10,000,000            
Swingline Loan              
Line of Credit Facility [Line Items]              
Sub limit for issuance of letters of credit   20,000,000.0          
Revolving line of credit facility, available borrowing capacity $ 20,000,000            
Previous Credit Facility              
Line of Credit Facility [Line Items]              
Line of credit facility, maximum borrowing capacity   $ 150,000,000.0