Pension Plans and Other Postretirement Benefits (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Amortization of:
Actuarial loss	$ 22,245
Total recognized in other comprehensive income (loss)	(5,645)		(1,276)		4,801
Weighted-average assumptions used to determine expense:
Discount rate	3.51%		2.95%		3.68%
Expected return on plan assets		[1]		[1]		[1]
Weighted-average assumptions used to determine benefit obligations as of December 31:
Discount rate	4.46%		3.51%		2.95%
Expected return on plan assets		[1]		[1]		[1]
Defined Benefit Plan [Member]
Service Cost
Benefit accrual	0		0		0
Other expenses	360		360		250
Interest cost	1,369		1,427		1,658
Expected return on plan assets	(2,238)		(2,423)		(2,419)
Settlement loss	867		1,209		1,290
Amortization of:
Prior service cost	0		0		0
Actuarial loss (gain)	1,602		2,367		1,824
Net periodic pension (benefit) expense	1,960		2,940		2,603
Changes in plan assets and benefit obligations included in other comprehensive income (loss):
Prior service cost	0		0		0
Net actuarial loss	(1,888)		115		4,951
Amortization of:
Prior service cost	0		0		0
Actuarial loss	(1,602)		(2,367)		(1,824)
Total recognized in other comprehensive income (loss)	(3,490)		(2,252)		3,127
Weighted-average assumptions used to determine expense:
Discount rate	3.51%		3.66%		4.58%
Expected return on plan assets	7.50%		7.50%		7.50%
Annual rate of salary increase		[1]		[1]		[1]
Weighted-average assumptions used to determine benefit obligations as of December 31:
Discount rate	4.46%		3.51%		3.66%
Expected return on plan assets	7.50%		7.50%		7.50%
Annual rate of salary increase		[1]		[1]		[1]
Supplemental Defined Benefit Plans [Member]
Service Cost
Benefit accrual	0		0		0
Other expenses	0		0		0
Interest cost	616		676		799
Expected return on plan assets	0		0		0
Settlement loss	0		0		0
Amortization of:
Prior service cost	124		124		125
Actuarial loss (gain)	203		171		698
Net periodic pension (benefit) expense	943		971		1,622
Changes in plan assets and benefit obligations included in other comprehensive income (loss):
Prior service cost	0		0		0
Net actuarial loss	(783)		817		1,755
Amortization of:
Prior service cost	(124)		(124)		(125)
Actuarial loss	(203)		(171)		(698)
Total recognized in other comprehensive income (loss)	$ (1,110)		$ 522		$ 932
Weighted-average assumptions used to determine expense:
Discount rate	3.51%		3.86%		4.92%
Expected return on plan assets		[1]		[1]		[1]
Annual rate of salary increase		[1]		[1]		[1]
Weighted-average assumptions used to determine benefit obligations as of December 31:
Discount rate	4.46%		3.51%		3.86%
Expected return on plan assets		[1]		[1]		[1]
Annual rate of salary increase		[1]		[1]		[1]

[1] Not applicable.