Pension and Postretirement Benefits (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2014
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 736		$ 728	$ 1,470	$ 1,566
Defined Benefit Plan, Interest Cost	1,519		1,398	3,061	2,778
Defined Benefit Plan, Expected Return on Plan Assets	(1,601)		(1,463)	(3,208)	(2,941)
Defined Benefit Plan, Amortization of Losses	759		991	1,548	1,972
Defined Benefit Plan, Amortization of Prior Service Cost	(15)		104	851	132
Defined Benefit Plan, Net Periodic Benefit Cost	1,398		1,758	3,722	3,507
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year						6,172
Defined Benefit Plan, Contributions by Employer				4,506
Effect of Plan Amendment on Net Periodic Benefit Cost		902
Prior Service Cost Charge per Diluted Share		$ 0.05
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	2		4	10	17
Defined Benefit Plan, Interest Cost	62		36	116	92
Defined Benefit Plan, Expected Return on Plan Assets	0		0	0	0
Defined Benefit Plan, Amortization of Losses	26		(31)	32	16
Defined Benefit Plan, Amortization of Prior Service Cost	0		0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	90		9	158	125
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year						607
Defined Benefit Plan, Contributions by Employer				$ 328