Retirement benefits (Tables)

6 Months Ended

Dec. 31, 2021

Retirement Benefits [Abstract]

Net pension benefit expense

Net pension benefit expense recognized included the following components:

	Three Months Ended				Six Months Ended
	December 31,				December 31,
	2021		2020		2021		2020
Service cost	$	18,699	$	19,389	$	39,361	$	42,199
Interest cost	27,559		25,755		54,988		51,172
Expected return on plan assets	(67,135)		(66,807)		(134,463)		(133,209)
Amortization of prior service cost	1,122		1,446		2,056		2,289
Amortization of net actuarial loss	41,085		52,829		78,616		105,160
Amortization of initial net obligation	2		4		4		9
Net pension benefit expense	$	21,332	$	32,616	$	40,562	$	67,620