Pension and Postretirement Benefits (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2014
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 716		$ 789	$ 2,186	$ 2,355
Defined Benefit Plan, Interest Cost	1,506		1,394	4,567	4,172
Defined Benefit Plan, Expected Return on Plan Assets	(1,588)		(1,476)	(4,796)	(4,417)
Defined Benefit Plan, Amortization of Losses	763		989	2,311	2,961
Defined Benefit Plan, Amortization of Prior Service Cost	(21)		23	830	155
Defined Benefit Plan, Net Periodic Benefit Cost	1,376		1,719	5,098	5,226
Defined Benefit Plan, Expected Contributions In Current Fiscal Year						5,257
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year						6,172
Defined Benefit Plan, Contributions by Employer				4,757
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	5		9	15	26
Defined Benefit Plan, Interest Cost	58		46	174	138
Defined Benefit Plan, Expected Return on Plan Assets	0		0	0	0
Defined Benefit Plan, Amortization of Losses	16		8	48	24
Defined Benefit Plan, Amortization of Prior Service Cost	0		0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	79		63	237	188
Defined Benefit Plan, Expected Contributions In Current Fiscal Year						607
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year						607
Defined Benefit Plan, Contributions by Employer				$ 432