Share-Based Compensation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017 Plans shares	Mar. 31, 2016 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of share-based compensation plans | Plans	2
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock and restricted stock units granted	43,385	120,376
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock and restricted stock units granted	221,297	247,510