Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Company's Debt Maturities on Calendar Year Basis (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Mar. 07, 2016	Dec. 31, 2015	Dec. 31, 2014	Mar. 18, 2013
Convertible Notes \| 1.50% Senior Subordinated Notes Due March 15, 2018
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	1.50%		1.50%	1.50%	1.50%
Principal amount of long term debt	$ 295.1				$ 400.0
Senior Secured Term Loan
Debt Instrument [Line Items]
Principal amount of long term debt	$ 263.7	$ 300.0