XML 61 R47.htm IDEA: XBRL DOCUMENT v3.19.1
Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]    
Amortization expense $ 6.7 $ 6.3
Impairment of Intangible Assets (Excluding Goodwill) 0.0 0.4
Capitalized software development costs    
Finite-Lived Intangible Assets [Line Items]    
Amortization expense $ 1.4 $ 0.9