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Stockholders' Equity - Summary of Number of PSUs Granted Based on Adjusted EBITDA and Grant Date Fair Value (Detail) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Number of units granted 20,587 71,893 101,062
PSUs – Adjusted EBITDA [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Number of units granted 165,391 158,964 239,851
Weighted average fair value on grant date $ 43.10 $ 46.05 $ 32.72