Options and Awards Options Outstanding by Exercise Price (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	1,313
Black-Scholes Fair Value	$ 15,400
Stock Options Vested and Exercisable	669
2005
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	$ 4.99
Exercise Price, Upper Range Limit	$ 5.75
Black-Scholes Fair Value	0	[1]
Remaining Contractual Life (Years)	1 year 0 months
2006
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	$ 7.05
Exercise Price, Upper Range Limit	$ 7.50
Black-Scholes Fair Value	771
Remaining Contractual Life (Years)	2 years 0 months
2008
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	$ 9.38
Exercise Price, Upper Range Limit	$ 14.87
Black-Scholes Fair Value	1,285
Remaining Contractual Life (Years)	4 years 0 months
2009
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	$ 14.88
Exercise Price, Upper Range Limit	$ 16.70
Black-Scholes Fair Value	1,989
Remaining Contractual Life (Years)	5 years 0 months
2010
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	$ 17.47
Exercise Price, Upper Range Limit	$ 18.16
Black-Scholes Fair Value	597
Remaining Contractual Life (Years)	6 years 0 months
2011
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	$ 21.61
Exercise Price, Upper Range Limit	$ 29.30
Black-Scholes Fair Value	959
Remaining Contractual Life (Years)	7 years 0 months
2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	$ 24.04
Exercise Price, Upper Range Limit	$ 29.16
Black-Scholes Fair Value	2,848
Remaining Contractual Life (Years)	8 years 0 months
2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	$ 29.25
Exercise Price, Upper Range Limit	$ 42.13
Black-Scholes Fair Value	4,062
Remaining Contractual Life (Years)	9 years 0 months
2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Upper Range Limit	$ 38.65
Black-Scholes Fair Value	$ 2,889
Remaining Contractual Life (Years)	10 years 0 months
Common Class A [Member] | 2005
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	20
Stock Options Vested and Exercisable	20
Common Class A [Member] | 2006
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	80
Stock Options Vested and Exercisable	80
Common Class A [Member] | 2008
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	233
Stock Options Vested and Exercisable	233
Common Class A [Member] | 2009
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	252
Stock Options Vested and Exercisable	203
Common Class A [Member] | 2010
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	67
Stock Options Vested and Exercisable	43
Common Class A [Member] | 2011
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	77
Stock Options Vested and Exercisable	29
Common Class A [Member] | 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	211
Stock Options Vested and Exercisable	44
Common Class A [Member] | 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	227
Stock Options Vested and Exercisable	17
Common Class A [Member] | 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Outstanding Options	146
Stock Options Vested and Exercisable	0

[1] The Company will not recognize the Black-Scholes fair value for awards granted prior to January 1, 2006 unless such awards are modified.