Pension and Other Postretirement Benefit Plans (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Components of net periodic benefit cost [Abstract]
Defined benefit plans employer contributions toward sponsored pension plans	$ 1,400,000
Anticipated contribution during current fiscal year	6,200,000
Aggregate contribution towards sponsored pension plans	7,600,000
Pension Benefits [Member]
Components of net periodic benefit cost [Abstract]
Service cost-benefits earned during the period	177,000	264,000
Interest cost on projected benefit obligation	2,354,000	2,654,000
Expected return on plan assets	(2,772,000)	(3,155,000)
Amortization of prior service (credit) cost	11,000	11,000
Amortization of (gain)/loss	311,000	50,000
Net periodic benefit cost	81,000	(176,000)
Total benefits cost (credited) charged to income	81,000	(176,000)
Other Benefits [Member]
Components of net periodic benefit cost [Abstract]
Service cost-benefits earned during the period	103,000	85,000
Interest cost on projected benefit obligation	860,000	876,000
Expected return on plan assets	0	0
Amortization of prior service (credit) cost	(9,000)	(9,000)
Amortization of (gain)/loss	101,000	77,000
Net periodic benefit cost	1,055,000	1,029,000
Total benefits cost (credited) charged to income	$ 1,055,000	$ 1,029,000