Quarterly report pursuant to Section 13 or 15(d)

Segment Information - Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Parenthetical) (Detail)

v3.10.0.1
Segment Information - Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Parenthetical) (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Selling, General and Administrative Expenses [Member] | China [Member]        
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]        
Independent service providers service fees costs $ 135.7 $ 99.5 $ 398.3 $ 316.9