Equity (Details) (USD $) In Thousands, except Share data in Millions, unless otherwise specified	1 Months Ended	6 Months Ended
	Aug. 08, 2012	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012	Feb. 10, 2012	Dec. 31, 2011
Common Stock Repurchase Authorized
Stock Repurchase Shares Authorized	4.0	4.6		5.0		2.2
Share repurchase authorization increase					2.8
Treasury Stock, Shares, Acquired	0.7	0.4
Treasury stock acquired in accounts payable		$ 1,969	$ 0