Summary of Capped Call (Equity Options) Issued (Detail) (Capped call (equity options), USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended
Nov. 30, 2010
Capped call (equity options)
Option Indexed to Issuer's Equity [Line Items]
Original Number of Options	8,433,123
Net Premium Paid	$ 50.3

The maximum number of shares that could be issued to net share settle a contract, if applicable. If a contract does not have a fixed or determinable maximum number of shares that may be required to be issued, disclose the fact that a potentially infinite number of shares could be issued to settle the contract.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 40

-Section 50

-Paragraph 5

-Subparagraph (b)(2),(c)

-URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008

Name:	us-gaap_OptionIndexedToIssuersEquityShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration