XML 45 R34.htm IDEA: XBRL DOCUMENT v3.8.0.1
Assets and Liabilities Measured at Fair Value (Parenthetical) (Detail) - USD ($)
$ in Millions
Mar. 31, 2018
Dec. 31, 2017
Collateral for Corporate Credit Card and Deposit    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Restricted cash $ 0.2 $ 0.1
Collateral for Redeemable Convertible Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Restricted cash   $ 5.2