XML 61 R50.htm IDEA: XBRL DOCUMENT v3.10.0.1
Asset Impairment - Additional information (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2018
Mar. 31, 2017
Sep. 30, 2018
Sep. 30, 2017
Asset Impairment Charges [Line Items]        
Asset impairment charge $ 27.1 $ 3.2 $ 27.1 $ 3.2
Definite-lived intangible assets   3.0    
Fixed Assets   $ 0.2