Earnings Per Share Computation of diluted weighted average shares outstanding (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Basic weighted average shares outstanding	50,827,767	51,116,512	50,705,222	51,134,940
Weighted Average Number Diluted Shares Outstanding Adjustment	769,552	0	815,981	762,558
Diluted weighted average shares outstanding	51,597,319	51,116,512	51,521,203	51,897,498
3.5% Issue [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Debt Instrument, Convertible, Number of Equity Instruments	4,200,000	4,200,000	4,200,000	4,200,000