Assets Measured Level 3 Fair Values on Non-Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Measurements, Nonrecurring \| Level 3
Fair Value Measurements On Nonrecurring Basis [Line Items]
Intangible assets	$ 14.9	$ 106.7

Fair value portion of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19190-110258

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