Stock-Based Compensation (Summary of Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Stock-based Compensation [Abstract]
Shares, Outstanding and Exercisable, Beginning of Period	22,500
Shares, Exercised		(1,450)
Shares, Outstanding and Exercisable, End of Period	22,500		22,500
Weighted Average Exercise Price, Outstanding and Exercisable at Beginning of Year	$ 10.41
Weighted Average Exercise Price, Exercised		$ 9.30
Weighted Average Exercise Price, Outstanding and Exercisable at End of Period	$ 10.41		$ 10.41
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	2 years	2 years 7 months 6 days	2 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding and Exercisable at End of Period	$ 762