Stock Repurchases (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2013
Stock Repurchases [Abstract]
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 100.0

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

No definition available.

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