Summary of Significant Accounting Policies (Details 6) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 02, 2012	Apr. 30, 2010
Details of stock benefit plans
Selling, general and administrative, stock-based compensation	$ 27,034,000	$ 62,875,000	$ 54,261,000
Long-Term Incentive Plan
Details of stock benefit plans
Number of shares of common stock that may be issued under the Plan				28,133,332	19,333,332
Selling, general and administrative, stock-based compensation	26,800,000	62,600,000	54,100,000
Shares available for future grant (in shares)	5,083,000
Long-Term Incentive Plan | Stock Options
Details of stock benefit plans
Number of shares of common stock that may be issued under the Plan	1,000,000
Options to purchase common stock outstanding (in shares)	7,910,000	9,436,000
Option vesting term (in years)	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Post-vesting cancellation rate used in valuation of options (as a percent)		0.00%
Shares
Options outstanding at the beginning of the period (in shares)	9,436,000
Granted (in shares)	1,244,000
Exercised (in shares)	(2,486,000)
Forfeited (in shares)	(283,000)
Expired (in shares)	(1,000)
Options outstanding at the end of the period (in shares)	7,910,000	9,436,000
Vested and expected to vest (in shares)	7,615,000
Options exercisable (in shares)	1,692,000
Weighted Avg. Exercise Price (in dollars per share)
Options outstanding at the beginning of the period (in dollars per share)	$ 15.04
Granted (in dollars per share)	$ 34.30
Exercised (in dollars per share)	$ 11.98
Forfeited (in dollars per share)	$ 18.56
Expired (in dollars per share)	$ 15.86
Options outstanding at the end of the period (in dollars per share)	$ 18.90	$ 15.04
Vested and expected to vest (in dollars per share)	$ 18.86
Options exercisable (in dollars per share)	$ 14.85
Weighted Avg. Remaining Contractual Term
Options outstanding at the end of the period (in years)	7 years 8 months 23 days
Vested and expected to vest (in years)	7 years 8 months 23 days
Options exercisable (in years)	7 years 3 months 4 days
Aggregate Intrinsic Value (in dollars)
Options outstanding at the end of the period (in dollars)	141,747,000
Vested and expected to vest (in dollars)	136,727,000
Options exercisable (in dollars)	37,173,000
Stock-based compensation additional disclosures
Weighted average grant date fair value of options granted (in dollars per share)	$ 7.78	$ 8.07	$ 6.91
Total intrinsic value of options exercised (in dollars)	57,100,000	68,000,000	6,900,000
Fair value of options vested during the period (in dollars)	18,000,000	15,700,000	10,300,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	16,400,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	2 years 8 months 5 days
Cash received from the exercise of stock option	29,800,000	40,000,000	9,100,000
Long-Term Incentive Plan | Stock Options | Chief executive officer
Weighted-average assumptions used to estimate the fair value of stock options granted
Risk-free interest rate (as a percent)	1.20%	1.08%	0.00%
Expected term (in years)	6 years 3 months	6 years 3 months	0 years
Expected volatility (as a percent)	39.21%	44.23%	0.00%
Expected dividend yield (as a percent)	5.24%	4.51%	0.00%
Long-Term Incentive Plan | Stock Options | Key employees
Weighted-average assumptions used to estimate the fair value of stock options granted
Risk-free interest rate (as a percent)	2.03%	1.08%	1.68%
Expected term (in years)	6 years 3 months	6 years 3 months	6 years 3 months
Expected volatility (as a percent)	38.98%	44.14%	43.68%
Expected dividend yield (as a percent)	5.08%	3.48%	0.65%
Long-Term Incentive Plan | Restricted Stock and Restricted Stock Units
Details of stock benefit plans
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	351,000	694,000
Stock-based compensation additional disclosures
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 800,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	6 months 28 days