XML 52 R42.htm IDEA: XBRL DOCUMENT v3.8.0.1
Asset Impairment - Additional information (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Mar. 31, 2017
Sep. 30, 2017
Asset Impairment Charges [Line Items]    
Asset impairment charge $ 3.2 $ 3.2
Definite-lived intangible assets 3.0  
Fixed Assets $ 0.2