Annual report pursuant to Section 13 and 15(d)

Employee Benefits (Details)

v2.4.1.9
Employee Benefits (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]      
Employer matching contribution percent 100.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch    
Employer matching percent 6.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent    
Employer contributions $ 4,556us-gaap_DefinedContributionPlanCostRecognized $ 4,524us-gaap_DefinedContributionPlanCostRecognized $ 3,605us-gaap_DefinedContributionPlanCostRecognized