Condensed Consolidated Statements of Equity (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Noncontrolling Interests [Member]	Total
Beginning Balances at Dec. 31, 2012	$ 1,230	$ 779,904	$ (6,165)	$ 1,103,188	$ 4,973	$ 1,883,130
Beginning Balances, shares at Dec. 31, 2012	123,019,494
Vesting of restricted stock units (shares)	476,603
Vesting of restricted stock units	5	(5)
Tax withholdings related to net share settlements of restricted stock units	(1)	(5,361)				(5,362)
Tax withholdings related to net share settlements of restricted stock units, shares	(150,396)
Equity-based compensation		7,446				7,446
Exercise of stock options and warrants	1	1,329				1,330
Exercise of stock options and warrants, shares	127,059
Excess tax benefit associated with equity-based compensation		2,667				2,667
Cash dividends on common stock				(24,654)		(24,654)
Amounts reclassified into earnings, net of taxes			1,716			1,716
Changes in fair value of cash flow hedges, net of taxes			1,161			1,161
Distributions to noncontrolling interests					(198)	(198)
Net income				85,523	151	85,674
Ending Balances at Jun. 30, 2013	1,235	785,980	(3,288)	1,164,057	4,926	1,952,910
Ending Balances, Shares at Jun. 30, 2013	123,472,760
Beginning Balances at Dec. 31, 2013	1,236	796,085	(1,869)	1,247,630	5,125	2,048,207
Beginning Balances, shares at Dec. 31, 2013	123,566,487					123,566,487
Vesting of restricted stock units (shares)	497,586
Vesting of restricted stock units	5	(5)
Tax withholdings related to net share settlements of restricted stock units	(2)	(6,727)				(6,729)
Tax withholdings related to net share settlements of restricted stock units, shares	(158,182)
Equity-based compensation		9,444				9,444
Exercise of stock options and warrants	2	2,956				2,958
Exercise of stock options and warrants, shares	210,902
Excess tax benefit associated with equity-based compensation		7,096				7,096
Cash dividends on common stock				(28,496)		(28,496)
Amounts reclassified into earnings, net of taxes			818			818
Changes in fair value of cash flow hedges, net of taxes			(1,429)			(1,429)
Distributions to noncontrolling interests					(371)	(371)
Net income				111,679	443	112,122
Ending Balances at Jun. 30, 2014	$ 1,241	$ 808,849	$ (2,480)	$ 1,330,813	$ 5,197	$ 2,143,620
Ending Balances, Shares at Jun. 30, 2014	124,116,793					124,116,793