Joint Ventures and Investments - Other Equity Investments (Parenthetical) (Detail) - China Outfitters Holdings Ltd. - Equity Investments - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Schedule Of Investments [Line Items]
Fair value investment	$ 1.0	$ 1.0
Other Income
Schedule Of Investments [Line Items]
Increase (decrease) in fair value investment	$ 0.1

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

Name:	us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant