Fair Value of Financial Instruments - Summary of Change in Estimated Fair Value of Company's Level 3 Financial Instrument (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Decrease in the value of private placement warrants	$ (9,299)	$ (6,169)	$ 28,031
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at beginning of year	11,036	24,525
Fair value of private placement warrants exercised	(255)	(7,320)
Decrease in the value of private placement warrants	(9,299)	(6,169)
Balance at end of year	$ 1,482	$ 11,036	$ 24,525