Stock-Based Compensation and Other Employee Benefit Plans (Summary of Stock-Based Compensation Expense and Related Tax Benefits) (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense					$ 11,584,000		$ 9,647,000
Income Tax Effects:
Income tax benefit from stock-based compensation	1,800,000		4,500,000		8,400,000		7,700,000
Excess tax benefit from stock-based compensation	100,000	[1]	3,000,000	[1]	3,494,000	[1]	4,446,000	[1]
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 4,100,000		$ 3,000,000		$ 11,600,000		$ 9,600,000

[1] Excess tax benefits, which represent cash flows from tax deductions in excess of the recorded tax effect of compensation expense recognized for stock options exercised and vested restricted shares, are classified as financing cash flows in the Company’s condensed unaudited consolidated statements of cash flows.