Shareholders' Equity (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended
May 31, 2012	Apr. 30, 2012
Shareholders' Equity [Abstract]
Share repurchase authorized amount	$ 100.0
Shares Purchased Outside Repurchase Program		70,278
Average per share price		$ 53.27

The amount authorized by an entity's Board of Directors under a stock repurchase plan.

No definition available.

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