Borrowings - 2022 Notes - Additional Information (Detail) - USD ($)		3 Months Ended
	Dec. 22, 2015	Mar. 31, 2016	Mar. 31, 2015
Schedule Of Debt Instruments [Line Items]
Debt maturity date		Jul. 15, 2020
Interest expense		$ 8,580,000	$ 4,566,000
2022 Notes [Member]
Schedule Of Debt Instruments [Line Items]
Debt instrument, aggregate principal amount	$ 175,000,000
Net proceeds from the debt issuance	$ 168,500,000
Interest rate (as a percent)	11.50%
Semi-annual installments of principal	$ 21,875,000
Debt maturity date	Dec. 15, 2022
Interest expense		$ 5,200,000