Debt - Summary of Redemption Prices Expressed as Percentage (Detail) - Senior Notes [Member]	12 Months Ended
Dec. 31, 2016
2017 [Member]
Debt Instrument Redemption [Line Items]
Redemption prices expressed as percentage	104.00%
2018 [Member]
Debt Instrument Redemption [Line Items]
Redemption prices expressed as percentage	102.00%
2019 and thereafter [Member]
Debt Instrument Redemption [Line Items]
Redemption prices expressed as percentage	100.00%

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration