Stockholders' Equity - Additional Information (Detail) In Millions, unless otherwise specified	Mar. 31, 2013
Shareholders Equity [Line Items]
Maximum number of shares authorized to be repurchased	10.6

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