XML 87 R73.htm IDEA: XBRL DOCUMENT v3.6.0.2
Employee Benefit Plans - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Employee Benefit Plans [Line Items]      
Minimum service period required 1 year    
Expense of employee related plan $ 0.8 $ 0.6 $ 0.5
Matching Contribution up to 3% [Member]      
Employee Benefit Plans [Line Items]      
Matching contribution 100.00% 100.00% 100.00%
Matching Contribution 3 to 5% [Member]      
Employee Benefit Plans [Line Items]      
Matching contribution 50.00% 50.00% 50.00%
Employee Contribution Matched at 100% [Member]      
Employee Benefit Plans [Line Items]      
Employee contribution 3.00% 3.00% 3.00%
Employee Contribution Matched at 50% [Member]      
Employee Benefit Plans [Line Items]      
Employee contribution 2.00% 2.00% 2.00%