Retirement benefits

6 Months Ended

Dec. 31, 2011

Retirement benefits

10. Retirement benefits

Net pension benefit cost recognized included the following components:

	Three Months Ended December 31,						Six Months Ended December 31,
	2011			2010			2011			2010
Service cost	$	21,000		$	20,020		$	42,624		$	41,890
Interest cost		46,823			43,573			92,739			86,845
Expected return on plan assets		(50,101	)		(49,201	)		(100,270	)		(97,934	)
Amortization of prior service cost		3,523			3,197			7,007			6,326
Amortization of net actuarial loss		27,046			28,361			52,460			54,159
Amortization of initial net (asset)		(15	)		(15	)		(30	)		(29	)
Net pension benefit cost	$	48,276		$	45,935		$	94,530		$	91,257

Net postretirement benefit cost recognized included the following components:

	Three Months Ended December 31,					Six Months Ended December 31,
	2011		2010			2011		2010
Service cost	$	181	$	136		$	362	$	275
Interest cost		881		980			1,762		1,962
Net amortization and deferral and other		129		(113	)		258		(228	)
Net postretirement benefit cost	$	1,191	$	1,003		$	2,382	$	2,009