Condensed Consolidated Statements of Equity (USD $) In Thousands, except Share data	Deferred Compensation Plan [Member] Common Stock [Member]	Common Stock [Member] USD ($)	Additional Paid-In Capital [Member] USD ($)	Accumulated Other Comprehensive Income (Loss) [Member] USD ($)	Retained Earnings [Member] USD ($)	Noncontrolling Interests [Member] USD ($)	Total USD ($)
Beginning Balances at Dec. 31, 2011		$ 1,109	$ 408,721	$ (3,480)	$ 988,560	$ 4,777	$ 1,399,687
Beginning Balances, shares at Dec. 31, 2011		110,907,782
Vesting of restricted stock units (shares)		591,165
Vesting of restricted stock units		6	(6)
Tax withholdings related to net share settlements of restricted stock units		(2)	(6,060)				(6,062)
Tax withholdings related to net share settlements of restricted stock units, shares		(189,939)
Equity-based compensation			17,289				17,289
Exercise of stock options and warrants		3	4,054				4,057
Exercise of stock options and warrants, shares		329,933
Excess tax benefit associated with equity-based compensation			5,033				5,033
Repurchase of common stock		(6)	(18,591)				(18,597)
Repurchase of common stock, shares		(619,447)
Cash dividends on common stock					(44,465)		(44,465)
Issuance of common stock, net of issuance costs of $376		120	369,464				369,584
Issuance of common stock, net of issuance costs of $376 (in shares)		12,000,000
Amounts reclassified into earnings, net of taxes				481			481
Changes in fair value of cash flow hedges, net of taxes				(3,166)			(3,166)
Distributions to noncontrolling interests						(198)	(198)
Divestiture of noncontrolling interest						(173)	(173)
Net income					159,093	567	159,660
Ending Balances at Dec. 31, 2012		1,230	779,904	(6,165)	1,103,188	4,973	1,883,130
Ending Balances, Shares at Dec. 31, 2012		123,019,494
Vesting of restricted stock units (shares)		482,403
Vesting of restricted stock units		5	(5)
Tax withholdings related to net share settlements of restricted stock units		(1)	(5,438)				(5,439)
Tax withholdings related to net share settlements of restricted stock units, shares		(152,191)
Equity-based compensation			15,397				15,397
Exercise of stock options and warrants		2	2,462				2,464
Exercise of stock options and warrants, shares		216,781
Excess tax benefit associated with equity-based compensation			3,765				3,765
Cash dividends on common stock					(51,213)		(51,213)
Amounts reclassified into earnings, net of taxes				3,483			3,483
Changes in fair value of cash flow hedges, net of taxes				813			813
Distributions to noncontrolling interests						(198)	(198)
Net income					195,655	350	196,005
Ending Balances at Dec. 31, 2013		1,236	796,085	(1,869)	1,247,630	5,125	2,048,207
Ending Balances, Shares at Dec. 31, 2013		123,566,487					123,566,487
Vesting of restricted stock units (shares)	10,665	492,695
Vesting of restricted stock units		5	(5)
Tax withholdings related to net share settlements of restricted stock units		(1)	(6,813)				(6,814)
Tax withholdings related to net share settlements of restricted stock units, shares		(159,936)
Equity-based compensation			18,446				18,446
Exercise of stock options and warrants		2	3,373				3,375
Exercise of stock options and warrants, shares		241,716
Excess tax benefit associated with equity-based compensation			7,518				7,518
Repurchase of common stock		(2)	(7,315)				(7,317)
Repurchase of common stock, shares		(167,100)
Cash dividends on common stock					(58,906)		(58,906)
Amounts reclassified into earnings, net of taxes				2,317			2,317
Changes in fair value of cash flow hedges, net of taxes				(6,041)			(6,041)
Distributions to noncontrolling interests						(371)	(371)
Net income					232,525	802	233,327
Ending Balances at Dec. 31, 2014		$ 1,240	$ 811,289	$ (5,593)	$ 1,421,249	$ 5,556	$ 2,233,741
Ending Balances, Shares at Dec. 31, 2014		123,984,527					123,984,527