Quarterly report pursuant to Section 13 or 15(d)

Debt - Additional Information (Details)

v2.4.0.8
Debt - Additional Information (Details) (USD $)
0 Months Ended 6 Months Ended
May 09, 2014
Jun. 30, 2014
Dec. 31, 2013
Jun. 30, 2014
Federal Funds Rate
Jun. 30, 2014
LIBOR
Jun. 30, 2014
LIBOR
Minimum
Jun. 30, 2014
LIBOR
Maximum
Jun. 30, 2014
Wells fargo's prime rate
Minimum
Jun. 30, 2014
Wells fargo's prime rate
Maximum
Jun. 30, 2014
Revolving Credit Facility
Jun. 30, 2014
Standby Letters of Credit
Line of Credit Facility [Line Items]                      
Revolving line of credit facility, available borrowing capacity   $ 125,000,000.0               $ 150,000,000.0  
Sub limit for issuance of letters of credit                     10,000,000.0
Basis spread on interest rate       0.50% 1.00% 2.00% 2.50% 0.00% 0.25%    
Authorized amount of common stock repurchase 75,000,000                    
Value of equipment in hands of employees, consultants, or customers   2,500,000.0                  
Aggregate permitted acquisition limit   150,000,000.0                  
Additional borrowing capacity under certain conditions   100,000,000.0                  
Revolving line of credit, outstanding amount   25,000,000 0                
Issuance of letters of credit outstanding, amount   10,000,000.0                  
Unamortized debt issuance costs   $ 200,000 $ 300,000