Retirement benefits (Tables)

9 Months Ended

Mar. 31, 2012

Pension Plans, Defined Benefit

Schedule of Defined Benefit Plans Disclosures

Net pension benefit cost recognized included the following components:

		$137,544			$137,544			$137,544			$137,544
	Three Months Ended March 31,						Nine Months Ended March 31,
	2012			2011			2012			2011
Service cost	$	21,350		$	21,139		$	63,974		$	63,029
Interest cost		45,981			43,852			138,720			130,697
Expected return on plan assets		(50,225	)		(49,196	)		(150,495	)		(147,130	)
Amortization of prior service cost		3,505			3,137			10,512			9,463
Amortization of net actuarial loss		26,706			27,370			79,166			81,529
Amortization of initial net (asset)		(15	)		(15	)		(45	)		(44	)
Net pension benefit cost	$	47,302		$	46,287		$	141,832		$	137,544

Other Postretirement Benefit Plans, Defined Benefit

Schedule of Defined Benefit Plans Disclosures

Net postretirement benefit cost recognized included the following components:

		$137,544		$137,544		$137,544		$137,544
	Three Months Ended March 31,				Nine Months Ended March 31,
	2012		2011		2012		2011
Service cost	$	183	$	233	$	545	$	508
Interest cost		838		724		2,600		2,686
Net amortization and deferral and other		92		621		350		393
Net postretirement benefit cost	$	1,113	$	1,578	$	3,495	$	3,587