Debt - Long-Term Debt Maturities (Parenthetical) (Detail) (USD $)	6 Months Ended
Jun. 30, 2014
Debt Disclosure [Abstract]
Conversion rate of notes to shares of common stock	25.8244
Base principal amount per note	$ 1,000
Conversion price of exchangeable notes	$ 38.72

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

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

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-Name Regulation S-X (SX)

-Number 210

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-Name Accounting Standards Codification

-Glossary Conversion Rate

-URI http://asc.fasb.org/extlink&oid=6509012

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