Stock-Based Compensation (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	6 Months Ended
	Mar. 31, 2013	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Stock-Based Compensation [Abstract]
Options, Granted		1,100
Options, Exercised		(7,433)
Share Price		$ 29.00	$ 27.05	$ 25.91
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		12 months
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized		$ 80
Common Stock, Dividend Rate, Percentage	10.00%	10.00%