Stock-Based Compensation Stock-Based Compensation Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 90	$ 15	$ 0	[1]
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	(365)	(286)	(67)
Allocated Share-based Compensation Expense, Net of Tax	589	461	109
share-based compensation expense, recognized in personnel expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	661	593	167
share-based compensation expense, recognized in other operating expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 293	$ 154	$ 9

[1] (1) The Company's ESPP began open enrollment in July 2011.