Equity and Earnings per Share - Narrative (Detail) - shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Participating securities (in shares)	497,491	537,337
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Participating securities (in shares)	0	128,500
Restricted Stock and Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Unvested awards (in shares)	497,491	665,837