Lon-Term Borrowings - Components of Long-term Borrowings (Parenthetical) (Detail)	1 Months Ended	9 Months Ended	12 Months Ended
Jul. 18, 2013	Sep. 30, 2013	Dec. 31, 2012
10.5% senior notes due 2018 [Member]
Debt Instrument [Line Items]
Interest rate		10.50%	10.50%
Due date		Apr. 15, 2018	Apr. 15, 2018
6.625% senior notes due 2021 [Member]
Debt Instrument [Line Items]
Interest rate	6.625%	6.625%	6.625%
Due date	Jul. 15, 2021	Jul. 15, 2021	Jul. 15, 2021

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

Reference 1: 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=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant