Subsequent Events - Additional Information (Detail) In Millions, unless otherwise specified	Jun. 30, 2012	Aug. 01, 2012 Repurchase of Equity
Subsequent Event [Line Items]
Number of additional shares authorized to be repurchased		10
Number of shares authorized to be repurchased	3.6

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

Name:	us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant