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Stock-based Compensation and Outstanding Awards - Summary of Status of Nonvested Shares of PSAs (Detail) - Performance Share (PSAs) Member]
12 Months Ended
Dec. 31, 2015
$ / shares
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Shares, Granted | shares 73,243
Nonvested shares, ending balance | shares 73,243
Weighted average grant date fair value, Granted | $ / shares $ 24.34
Weighted average grant date fair value, Nonvested ending balance | $ / shares $ 24.34