XML 102 R87.htm IDEA: XBRL DOCUMENT v3.8.0.1
Commitments and Contingencies - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]      
Operating leases, rent expense $ 5.5 $ 5.2 $ 4.5
Guarantees $ 3.5 $ 4.7