Shareholders' Equity Shareholders' Equity (Details textual) (USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended		3 Months Ended
	Mar. 09, 2012	Feb. 28, 2011	Mar. 31, 2012 Common Stock and Additional Paid-in Capital	Mar. 31, 2012 Retained Earnings
Stockholders Equity Note [Line Items]
Common stock repurchased, shares (in shares)			1.0
Common stock authorized to be repurchased, number of shares (in shares)		20.0
Common stock dividends, paid per share (in dollars per share)	$ 0.07
Common stock dividends, total cash paid				$ 10.8