Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation and Cash-Based Incentive Compensation - Summary of Incentive Compensation Expense under Share-Based Payment Arrangements and Related Tax Benefit (Details)

v2.4.1.9
Share-Based Compensation and Cash-Based Incentive Compensation - Summary of Incentive Compensation Expense under Share-Based Payment Arrangements and Related Tax Benefit (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Share-based compensation $ 2,816us-gaap_ShareBasedCompensation $ 3,758us-gaap_ShareBasedCompensation
Tax benefit computed at the statutory rate 986us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense 1,315us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Restricted Shares    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Share-based compensation 93us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember 		99us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Restricted Stock Units (RSUs)    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Share-based compensation 2,817us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember 		2,537us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
Common Stock    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Share-based compensation $ (94)us-gaap_ShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		$ 1,122us-gaap_ShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember