Stock Repurchase Program (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended
Feb. 16, 2012
Stock Repurchase Program
Repurchase of common stock authorized by board of directors	$ 100.0

Amount of a stock repurchase plan authorized by an entity's Board of Directors.

No definition available.

Name:	us-gaap_StockRepurchaseProgramAuthorizedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration