XML 66 R52.htm IDEA: XBRL DOCUMENT v3.6.0.2
Leases - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Operating Leased Assets [Line Items]      
Rent expense $ 7.0 $ 6.0 $ 5.2
Minimum [Member]      
Operating Leased Assets [Line Items]      
Lease extension period 1 year    
Maximum [Member]      
Operating Leased Assets [Line Items]      
Lease extension period 10 years