Stock and Incentive Compensation Plans - Summary of Restricted Stock and Restricted Stock Units (Detail) - Restricted Stock and Restricted Stock Units [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Beginning Balance, Shares	1,098	1,404	1,808
Granted	810	591	477
Restricted stock vested	(552)	(781)	(862)
Forfeited	(7)	(116)	(19)
Restricted Stock Ending Balance, Shares	1,349	1,098	1,404
Restricted stock and restricted stock units vested at December 31, 2016	134
Restricted Stock Beginning Balance, Weighted Average Grant Date Fair Value	$ 3.16	$ 2.44	$ 1.48
Granted, Weighted Average Grant Date Fair Value	3.94	3.24	3.64
Restricted stock vested, Weighted Average Grant Date Fair Value	2.75	2.03	1.13
Forfeited, Weighted Average Grant Date Fair Value	3.28	3.45	1.37
Restricted Stock Ending Balance, Weighted Average Grant Date Fair Value	3.64	$ 3.16	$ 2.44
Restricted stock and restricted stock units vested, Weighted Average Grant Date Fair Value	$ 2.56
Restricted Stock Outstanding, Average Remaining Contractual Term (Years)	8 years 3 months 18 days
Restricted Outstanding, Aggregate Intrinsic Value	$ 8,825
Restricted stock and restricted stock units vested, Aggregate Intrinsic Value	$ 874
Restricted Stock Outstanding, Average Remaining Vesting Period (months)	7 months 21 days
Restricted Stock Outstanding, Unrecognized Compensation Expense	$ 2,973