Additional Information about Assets and Liabilities That Are Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 36,704	$ 48,486
Change in fair value of financial instruments	5,518	(11,782)
Ending Balance	42,222	36,704
Warrants and investor SARs
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	26,200	35,384
Change in fair value of financial instruments	4,200	(9,184)
Ending Balance	30,400	26,200
Junior Subordinated Notes, at Fair Value
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	10,504	13,102
Change in fair value of financial instruments	1,318	(2,598)
Ending Balance	$ 11,822	$ 10,504