Retirement Plans (Schedule of Benefit Plan Funded Status) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Retirement Plans [Abstract]
Benefit obligation at beginning of year	$ 20,989	$ 17,919
Change in benefit obligation: Service cost	651	570	458
Change in benefit obligation: Interest cost	925	962	1,074
Change in benefit obligation: Actuarial loss	2,590	2,303
Change in benefit obligation: Benefits paid	(858)	(765)
Benefit obligation at end of year	24,297	20,989	17,919
Fair value of plan assets at beginning of year	25,451	23,760
Change in plan assets: Actual return on plan assets	2,969	1
Change in plan assets: Employer contribution	1,856	2,455
Change in plan assets: Benefits paid	(858)	(765)
Fair value of plan assets at end of year	29,418	25,451	23,760
Funded Status, included in other assets	5,121	4,462
Amounts recognized in accumulated other comprehensive income: Total net actuarial loss	8,719	7,937
Amounts recognized in accumulated other comprehensive income: Transition obligation		10
Amounts recognized in accumulated other comprehensive income: Prior service cost	105	144
Total included in accumulated other comprehensive income (pretax)	$ 8,824	$ 8,091