Stock-Based Compensation Plans (Schedule of Compensation Expense Recognized in Connection with Restricted Stock Awards and MSPP) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restricted Stock Awards and Management Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense	$ 228	$ 129	$ 91
Related income tax benefit	80	45	32
Fair value of grants vested	121	106	134
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense	163	92	72
Management Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense	$ 65	$ 37	$ 19