Share-Based Compensation - Schedule of Deferred Stock Units to be Settled in Shares (Detail) shares in Thousands	3 Months Ended
	Mar. 31, 2017 $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning balance of Outstanding, Deferred Stock Units to be Settled in Shares | shares	76	[1]
Granted, Deferred Stock Units to be Settled in Shares | shares	0
Vested, Deferred Stock Units to be Settled in Shares | shares	0
Forfeited, Deferred Stock Units to be Settled in Shares | shares	0
Ending balance of Outstanding, Deferred Stock Units to be Settled in Shares | shares	76	[1]
Beginning balance of Outstanding, Weighted Average Grant-Date Fair Value Per Unit | $ / shares	$ 4.44	[1]
Granted, Weighted Average Grant-Date Fair Value Per Unit | $ / shares	0
Vested, Weighted Average Grant-Date Fair Value Per Unit | $ / shares	0
Forfeited, Weighted Average Grant-Date Fair Value Per Unit | $ / shares	0
Ending balance of Outstanding, Weighted Average Grant-Date Fair Value Per Unit | $ / shares	$ 4.44	[1]

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