Pension and Post-retirement Benefits (Tables)

6 Months Ended

Mar. 31, 2017

Pension and Post-retirement Benefits

Schedule of components of net periodic pension and postretirement benefit cost

	Three Months Ended March 31,								Six Months Ended March 31,
	Pension Benefits				Other Benefits				Pension Benefits				Other Benefits
	2016		2017		2016		2017		2016		2017		2016		2017
Service cost	$	1,020	$	1,570	$	58	$	87	$	2,040	$	3,141	$	116	$	174
Interest cost		2,865		2,592		1,149		1,073		5,713		5,141		2,298		2,146
Expected return		(3,399)		(3,531)		—		—		(6,775)		(7,003)		—		—
Amortizations		2,385		2,994		706		1,070		4,766		5,975		1,412		2,140
Net periodic benefit cost	$	2,871	$	3,625	$	1,913	$	2,230	$	5,744	$	7,254	$	3,826	$	4,460