Pension Plan and Postretirement Benefits Other Than Pension (Details 2) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Components of net periodic benefit cost:
Percentage of net periodic pension and other postretirement benefit costs included in Compensation and related costs			60.00%
Pension Benefits
Components of net periodic benefit cost:
Service cost	$ 2,317,000	$ 2,556,000	$ 5,042,000	$ 5,506,000
Interest cost	2,045,000	1,903,000	4,198,000	3,855,000
Expected return on plan assets	(3,595,000)	(2,889,000)	(7,008,000)	(5,593,000)
Actuarial (gain) loss amortization	337,000	1,034,000	748,000	2,284,000
Prior service cost amortization	104,000	139,000	234,000	278,000
Transition obligation amortization	1,000	1,000	2,000	2,000
Total	1,209,000	2,744,000	3,216,000	6,332,000
Expected benefit payments
Employer contributions			20,000,000
Other Postretirement Benefits
Components of net periodic benefit cost:
Service cost	180,000	197,000	360,000	394,000
Interest cost	99,000	90,000	198,000	180,000
Actuarial (gain) loss amortization	(4,000)		(8,000)
Prior service cost amortization	14,000	14,000	28,000	28,000
Total	$ 289,000	$ 301,000	$ 578,000	$ 602,000