Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Stock-Based Compensation (Narrative) (Details)

v2.4.0.8
Stock-Based Compensation Stock-Based Compensation (Narrative) (Details) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Shares authorized 10,400,000    
Shares available for future grants 2,187,824    
Tax benefit for the deduction from stock-based award transactions $ 4,793,000 $ 3,410,000 $ 4,702,000
Stock-based compensation expense 8,878,000 7,833,000 7,870,000
Stock Options [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Stock-based compensation expense 3,479,000 3,180,000 3,550,000
Unrecognized costs related to share based compensation 5,637,000    
Weighted average period of recognition of unrecognized costs related to stock options, years 2 years 2 months 23 days    
Intrinsic value of stock options exercised 7,491,000 5,517,000 4,906,000
Cash received on exercises of stock options 19,537,000 14,600,000 10,991,000
Stock Options [Member] | After2000 And Before2009 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 4 years    
Expiration period, years 10 years    
Stock Options [Member] | During2005 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 1 year    
Expiration period, years 10 years    
Stock Options [Member] | After2008 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 4 years    
Expiration period, years 10 years    
Service Based Restricted Stock Units [Member] | After2008 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 4 years    
Service Based Restricted Stock Units [Member] | Prior To2009 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 3 years    
Performance Based Restricted Stock Units [Member] | Prior To2010 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Additional requisite service period, years 1 year    
Performance Based Restricted Stock Units [Member] | Minimum [Member] | Prior To2010 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 2 years 6 months    
Performance Based Restricted Stock Units [Member] | Minimum [Member] | After2009 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 2 years    
Performance Based Restricted Stock Units [Member] | Maximum [Member] | Prior To2010 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 3 years    
Performance Based Restricted Stock Units [Member] | Maximum [Member] | After2009 [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years 3 years    
Restricted Stock Units (RSUs) [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Stock-based compensation expense 5,399,000 4,653,000 4,320,000
Unrecognized costs related to share based compensation 10,640,000    
Weighted average period of recognition of unrecognized costs related to stock options, years 2 years 3 months 4 days    
Company withheld shares 41,683 30,299 48,059
Company withheld shares, tax obligations 2,291,000 1,486,000 2,974,000
Grant date fair value of vested units $ 5,362,000 $ 3,874,000 $ 5,586,000
Simplified Method [Member]
     
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Vesting period of options granted, years   5 years