Shareholders' Protection Rights Agreement - Additional Information (Detail)	Jun. 30, 2012
Stockholders Equity Note [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	15.00%
Shareholders' Protection Rights Agreement
Stockholders Equity Note [Line Items]
Common shares reserved for issuance in connection with its stock incentive plans	149,630,598
Holders of Shareholders' Rights would be entitled to purchase one common share, exercise price	160

Percentage of voting equity interests acquired in the business combination.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6909870&loc=d3e1392-128463

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant