Stock-Based Compensation (Details 9) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended			0 Months Ended		12 Months Ended	0 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 28, 2012 Class A common stock	Dec. 01, 2011 Class A common stock	Dec. 31, 2011 Class A common stock	Dec. 28, 2012 Class B common stock	Dec. 01, 2011 Class B common stock	Dec. 31, 2011 Class B common stock	Dec. 31, 2013 Stock options	Dec. 31, 2012 Stock options	Dec. 31, 2011 Stock options	Dec. 31, 2013 Stock options Minimum	Dec. 31, 2012 Stock options Minimum	Dec. 31, 2011 Stock options Minimum	Dec. 31, 2013 Stock options Maximum	Dec. 31, 2012 Stock options Maximum	Dec. 31, 2011 Stock options Maximum	Dec. 31, 2013 Stock option adjustment 2012	Dec. 31, 2012 Stock Option Adjustment 2011
Stock-Based Compensation
Non-cash stock-based compensation expense recognized	$ 30,655	$ 40,970	$ 31,521																$ 5,000	$ 14,000
Black-Scholes option valuation model, assumptions
Risk free interest rate, low end of range (as a percent)										0.91%	0.41%	0.36%
Risk free interest rate, high end of range (as a percent)										2.66%	1.29%	3.18%
Volatility factor, low end of range (as a percent)										32.37%	33.15%	31.74%
Volatility factor, high end of range (as a percent)										39.87%	39.50%	45.56%
Expected term of options													5 years 7 months 6 days	3 years 1 month 6 days	3 years 7 months 6 days	10 years	5 years 10 months 24 days	10 years
Weighted-average fair value of options granted (in dollars per share)													$ 14.49	$ 6.72	$ 8.73	$ 21.09	$ 13.79	$ 14.77
Dividend in cash per share (in dollars per share)				$ 1.00	$ 2.00	$ 2.00	$ 1.00	$ 2.00	$ 2.00
Dividend yield (as a percent)	0.00%	0.00%	0.00%