Stock Based Compensation (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of estimated forfeitures, minimum (in hundredths)	0.00%			0.00%	0.00%	0.00%
Percentage of estimated forfeitures, maximum (in hundredths)	10.00%			10.00%	10.00%	10.00%
Shares Granted (in shares)	128	85	1,286
Value Per Share, minimum (in dollars per share)	$ 16.66	$ 18.72	$ 17.39
Value Per Share, maximum (in dollars per share)	$ 17.74	$ 19.55	$ 19.07
Total Value	$ 2,135	$ 1,666	$ 24,524