Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Line Items]
Required distribution , REIT taxable income									90.00%
U.S. federal statutory rate									35.00%
(Provision) benefit for income taxes	$ 12,136,000	$ 12,450,000	$ 1,784,000	$ 66,292,000	$ 1,236,000	$ 16,581,000	$ (11,314,000)	$ (4,469,000)	$ 92,662,000	$ 2,034,000	$ (7,420,000)
Deferred tax benefit									(89,530,000)	(9,105,000)	5,399,000
Charitable contribution carryforwards	3,300,000								3,300,000
Valuation allowances related to federal deferred tax assets									60,300,000	(500,000)	(300,000)
State net operating loss carryforwards	486,500,000								486,500,000
Deferred tax benefit									(4,612,000)	(1,690,000)	1,237,000
Company's reserve for unrecognized tax benefits									12,327,000
Income Tax benefit									5,500,000
Company's reserve for unrecognized tax benefits decreased									835,000	764,000	709,000
Interest expense on uncertain tax positions	(1,500,000)								(2,200,000)	200,000	200,000
Additional income tax benefit									500,000
Unrecognized tax benefits					13,162,000					13,162,000	14,141,000	18,952,000
Penalty expense on uncertain tax positions									0	0	0
Interest on income taxes accrued related to uncertain tax positions	0				2,200,000				0	2,200,000
Income tax penalties accrued related to uncertain tax positions	0				0				0	0
Charitable Contributions [Member]
Income Tax Disclosure [Line Items]
Deferred tax benefit									(100,000)
Operating loss carryforwards expire date									2014
REIT Conversion [Member]
Income Tax Disclosure [Line Items]
(Provision) benefit for income taxes				61,300,000					64,800,000
Federal [Member]
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards	49,900,000								49,900,000
Deferred tax benefit									17,500,000
Operating loss carryforwards expire date									2032
Federal credit carryforwards	1,600,000								1,600,000
Federal credit carryforwards expire date									2031
State [Member]
Income Tax Disclosure [Line Items]
Federal credit carryforwards	100,000								100,000
Valuation allowances related to federal deferred tax assets									19,000,000	(300,000)	1,500,000
Deferred tax benefit									$ (25,600,000)
State [Member] | Minimum [Member]
Income Tax Disclosure [Line Items]
Operating loss carryforwards expire date									2014
State [Member] | Maximum [Member]
Income Tax Disclosure [Line Items]
Operating loss carryforwards expire date									2033