Income Taxes - Differences Between the Income Tax (Provision) Benefit Calculated at the Statutory U.S. Federal Income Tax Rate of 35% and the Actual Income Tax (Provision) Benefit Recorded for Continuing Operations (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Statutory federal income tax provision										$ (44,431)	$ (56,914)	$ (34,774)
Adjustment for nontaxable income of the REIT										38,272	48,680	34,904
State taxes (net of federal tax benefit)										(1,317)	(1,705)	(740)
Permanent share-based compensation adjustment										1,446	1,571
Other permanent items										(251)	(200)	(165)
Federal valuation allowance reversal										36,156	5,519	8,271
State valuation allowance reversal (net of federal tax benefit)										17,241	(228)	(737)
Effect of federal tax law change	$ 5,200	$ 2,000								2,030		5,229
Other										9	(123)	(133)
Total (provision) benefit for income taxes		$ 51,177	$ (530)	$ (899)	$ (593)	$ (1,048)	$ (1,822)	$ (1,415)	$ 885	$ 49,155	$ (3,400)	$ 11,855