Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended	11 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Nov. 30, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Line Items]
U.S. federal statutory rate					35.00%
Effect of federal tax law change	$ 5,200,000	$ 2,000,000			$ 2,030,000		$ 5,229,000
Built-in-gains recognition period	5 years		10 years
Recognized income tax benefit associated with release of valuation allowance		53,400,000			53,400,000
Deferred tax benefit		113,728,000			113,728,000	$ 157,150,000
Charitable contribution carryforwards		2,900,000			2,900,000
Increase decrease in federal and state valuation allowance					(74,000,000)
State net operating loss carryforwards		454,600,000			454,600,000
Unrecognized tax benefits		0			0	0
Income tax penalties accrued related to uncertain tax positions		0			0	0
Interest on income taxes accrued related to uncertain tax positions		0			0	0
Charitable Contributions [Member]
Income Tax Disclosure [Line Items]
Deferred tax benefit		600,000			$ 600,000
Operating loss carryforwards expire date					2018
Scenario, Forecast [Member]
Income Tax Disclosure [Line Items]
U.S. federal statutory rate				21.00%
Federal [Member]
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards		89,100,000			$ 89,100,000
Deferred tax benefit		18,700,000			$ 18,700,000
Operating loss carryforwards expire date					2033
Increase decrease in federal and state valuation allowance					$ (60,600,000)	600,000	(8,300,000)
State [Member]
Income Tax Disclosure [Line Items]
Deferred tax benefit		$ 26,100,000			26,100,000
Increase decrease in federal and state valuation allowance					$ (13,400,000)	$ (200,000)	$ (1,800,000)
State [Member] | Minimum [Member]
Income Tax Disclosure [Line Items]
Operating loss carryforwards expire date					2018
State [Member] | Maximum [Member]
Income Tax Disclosure [Line Items]
Operating loss carryforwards expire date					2037