Pension and Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2016

General Discussion Of Pension And Other Postretirement Benefits [Abstract]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

	Three Months Ended September 30,								Nine Months Ended September 30,
					Other								Other
					Postretirement								Postretirement
	Pension Benefits				Benefits				Pension Benefits				Benefits
		2016		2015		2016		2015		2016		2015		2016		2015
Service cost	$	672	$	763	$	—	$	1	$	2,025	$	2,297	$	8	$	12
Interest cost		1,111		1,256		28		47		3,344		3,772		106		146
Expected return on plan assets		(1,329)		(1,367)		—		—		(4,027)		(4,165)		—		—
Actuarial loss (gain) amortization		769		862		(30)		12		2,389		2,620		—		64
Prior service cost amortization		(25)		(25)		—		—		(76)		(76)		—		—
Net periodic benefit cost	$	1,198	$	1,489	$	(2)	$	60	$	3,655	$	4,448	$	114	$	222