Income Taxes - Changes in Deferred Tax Asset Valuation Allowances (Detail) - Valuation Allowance of Deferred Tax Assets - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Balance at the beginning of the year	$ (125,134)	$ (107,174)	$ (87,623)
Charged to provision for income taxes:
Other state valuation allowances	16,380	(23,790)	500
Other federal valuation allowances	494	(247)	(477)
Other	123	2,304	(1,100)
Balance at the end of the year	(120,347)	(125,134)	(107,174)
State
Charged to provision for income taxes:
Net operating loss carryforwards	(23,926)	(11,612)	(17,374)
Federal
Charged to provision for income taxes:
Net operating loss carryforwards	$ 11,716	$ 15,385	$ (1,100)