Retirement and Postretirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	4,650	5,729	13,950	17,185
Expected return on plan assets	(6,950)	(7,727)	(20,850)	(23,180)
Amortization of net loss	0	200	0	600
Net periodic benefit (income) cost	(2,300)	(1,798)	(6,900)	(5,395)
Other Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0	25	0	75
Interest cost	125	250	525	750
Expected return on plan assets	0	0	0	0
Amortization of net loss	(25)	0	(75)	0
Net periodic benefit (income) cost	$ 100	$ 275	$ 450	$ 825