CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Parent	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Deferred Compensation Employee Stock Trust, Net	Employee Stock Trust	Noncontrolling Interest	Total
Balance at Dec. 31, 2013	$ 1,311,141	$ 114,068	$ 902	$ 1,388,641	$ (34,863)	$ (157,607)			$ 781	$ 1,311,922
Balance (in shares) at Dec. 31, 2013		114,000	90,176,000
Increase (Decrease) in Stockholders' Equity
Net income	25,186					25,186			110	25,296
Other comprehensive income	18,809				18,809					18,809
Stock-based compensation expense	735			735						735
Common stock issued to board members	52			52						52
Common stock issued to board members (in shares)			2,000
Dividends on preferred stock	(1,426)			(1,426)						(1,426)
Cash distributions to noncontrolling interest									(175)	(175)
Balance at Mar. 31, 2014	1,354,497	114,068	902	1,388,002	(16,054)	(132,421)			716	1,355,213
Balance (in shares) at Mar. 31, 2014		114,000	90,178,000
Balance at Dec. 31, 2014	1,460,452	114,068	902	1,390,788	651	(45,957)			787	1,461,239
Balance (in shares) at Dec. 31, 2014		114,000	90,182,000
Increase (Decrease) in Stockholders' Equity
Net income	114,828					114,828			353	115,181
Other comprehensive income	5,099				5,099					5,099
Issuance of common stock	200,033		101	199,932						200,033
Issuance of common stock (in shares)			10,102,000
Stock-based compensation expense	1,814			1,814						1,814
Common stock issued to board members	51			51						51
Common stock issued to board members (in shares)			2,000
Dividends on preferred stock	(1,426)					(1,426)				(1,426)
Deferred compensation plan	592						1,189	(597)		592
Deferred compensation plan (in shares)								30,000
Cash distributions to noncontrolling interest									(264)	(264)
Balance at Mar. 31, 2015	$ 1,781,443	$ 114,068	$ 1,003	$ 1,592,585	$ 5,750	$ 67,445	$ 1,189	$ (597)	$ 876	$ 1,782,319
Balance (in shares) at Mar. 31, 2015		114,000	100,286,000					30,000