Pension and Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2017

General Discussion Of Pension And Other Postretirement Benefits [Abstract]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

	Three Months Ended March 31,
					Other
	Pension Benefits				Postretirement Benefits
		2017		2016		2017		2016
Service cost	$	918	$	670	$	3	$	4
Interest cost		1,008		1,111		33		39
Expected return on plan assets		(1,326)		(1,344)		—		—
Actuarial loss amortization		869		808		5		15
Prior service cost amortization		(23)		(25)		—		—
Net periodic benefit cost	$	1,446	$	1,220	$	41	$	58