Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Non-Cash Stock-Based Compensation Expense and Related Tax Benefits) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Non-cash stock-based compensation expense				$ 11,291	$ 9,486
Income Tax Effects:
Income tax benefit from non-cash stock-based compensation		$ 1,700	$ 1,200	5,600	3,700
Excess tax benefit from non-cash stock-based compensation	[1]	300	0	1,385	56
General and Administrative Expenses [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Non-cash stock-based compensation expense		$ 3,900	$ 3,200	$ 11,300	$ 9,500

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