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Earnings per Share - Additional Information (Detail) - shares
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Earnings Per Share [Line Items]      
Anti-dilutive shares of common stock excluded from the computation of diluted earnings per share 1,879,000 21,000 0
Shares included in calculation of diluted earnings per share 121,000 297,000 615,000
Performance-vesting Restricted Share [Member]      
Earnings Per Share [Line Items]      
Shares included in calculation of diluted earnings per share 19,000 0 0