Acquisition - (Schedule of Assets and Liabilities Acquired) (Detail) - USD ($) $ in Thousands	May 30, 2017	Mar. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 286,249	$ 312,441	$ 304,805
Uniwheels Acquisition [Member]
Business Acquisition [Line Items]
Cash consideration	703,000
Non-controlling interest	63,200
Cash and cash equivalents	12,296
Accounts receivable	60,580
Inventories	83,901
Prepaid expenses and other current assets	11,859
Total current assets	168,636
Property and equipment	259,784
Intangible assets	205,000		$ 205,000
Goodwill	286,249
Other assets	32,987
Total assets acquired	952,656
Accounts payable	61,883
Other current liabilities	40,903
Total current liabilities	102,786
Other long-term liabilities	83,670
Total liabilities assumed	186,456
Net assets acquired	$ 766,200