Retirement Plans (Changes in the Projected Benefit Obligation and Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 115,177	$ 100,216
Service cost	1,247	1,168	1,133
Interest cost	4,603	4,795	4,779
Defined Benefit Plan, Plan Amendments	0	0
Net actuarial (gain) loss	(10,926)	13,200
Benefits paid	(4,187)	(4,202)
Benefit obligation at end of year	105,914	115,177	100,216
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	98,187	82,521
Actual return on plan assets	19,829	7,868
Employer contributions	15,000	12,000
Benefits paid	(4,187)	(4,202)
Fair value of plan assets at end of year	128,829	98,187	82,521
Funded (unfunded) projected benefit obligation at end of year	22,915	(16,990)
Accumulated benefit obligation	99,551	108,078
Postretirement Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	3,243	3,290
Service cost	18	0	0
Interest cost	143	146	167
Defined Benefit Plan, Plan Amendments	720	0
Net actuarial (gain) loss	(428)	25
Benefits paid	(219)	(218)
Benefit obligation at end of year	3,477	3,243	3,290
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	219	218
Benefits paid	(219)	(218)
Fair value of plan assets at end of year	0	0	0
Funded (unfunded) projected benefit obligation at end of year	(3,477)	(3,243)
Accumulated benefit obligation	$ 3,477	$ 3,243