Long-Term Debt and Other Liabilities - Summary of Redemption Prices Plus Accrued and Unpaid Interest (Detail) - 12.500% Senior Secured Notes Due 2022 [Member]	3 Months Ended
	Mar. 31, 2018
2019 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument redemption price, percentage	106.25%
2020 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument redemption price, percentage	103.125%
2021 and Thereafter [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument redemption price, percentage	100.00%