Pension Plans and Other Postretirement Benefits (Details 4) (Postretirement Benefit Costs [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Postretirement Benefit Costs [Member]
Change in accumulated postretirement benefit obligations:
Accumulated postretirement benefit obligations at beginning of year	$ 1,130	$ 2,862	$ 3,326
Changes during fiscal year
Service cost	0	0	0
Interest cost	46	92	91
Plan amendment	0	(1,393)	0
Settlements	(965)	0	0
Employer payments net of participant contributions	(95)	(491)	(488)
Actuarial (gain) loss	(116)	60	(67)
Accumulated postretirement benefit obligations at end of year	0	1,130	2,862
Unfunded status	0	(1,130)	(2,862)
Total amount recognized in Consolidated Balance Sheets, all in other liabilities	0	(1,130)	(2,862)
Amounts recognized in accumulated other comprehensive income (loss) ("AOCI"):
Prior service cost	0	(1,341)	0
Net actuarial loss	0	(604)	(900)
Total amount recognized in AOCI	$ 0	$ (1,945)	$ (900)