Share-Based Compensation - Schedule of Deferred Stock Units to be Settled in Shares (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning balance of Outstanding Shares	90,642	[1]	116,952
Granted, Shares			2,928		116,952
Vested, Shares	(14,619)		(19,492)
Forfeited, Shares			(9,746)
Ending balance of Outstanding Shares	76,023	[1]	90,642	[1]	116,952
Beginning balance of Weighted Average Grant-Date Fair Value Per Unit	$ 4.43	[1]	$ 4.39
Granted, Weighted Average Grant-Date Fair Value Per Unit			5.73		$ 4.39
Vested, Weighted Average Grant-Date Fair Value Per Unit	4.39		4.39
Forfeited, Weighted Average Grant-Date Fair Value Per Unit			4.39
Ending balance of Weighted Average Grant-Date Fair Value Per Unit	$ 4.44	[1]	$ 4.43	[1]	$ 4.39

[1] Includes vested but unreleased awards. These awards are included in total outstanding awards until they are released under the terms of the agreement.