Retirement Benefits (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Pension Plans, Defined Benefit
Defined Benefit Plans Disclosure
Defined Benefit Plan, Service Cost	$ 24,506	$ 24,935	$ 74,163	$ 74,621
Defined Benefit Plan, Interest Cost	44,447	48,034	135,245	143,043
Defined Benefit Plan, Expected Return on Plan Assets	(54,658)	(56,657)	(164,847)	(169,619)
Defined Benefit Plan, Amortization of Prior Service Cost	2,306	2,949	6,903	8,843
Defined Benefit Plan, Amortization of Net Actuarial Loss	38,171	39,914	114,896	119,593
Defined Benefit Plan, Amortization of initial net obligations (assets)	4	5	13	15
Defined Benefit Plan, Net pension benefit cost	54,776	59,180	166,373	176,496
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plans Disclosure
Defined Benefit Plan, Service Cost	163	54	475	466
Defined Benefit Plan, Interest Cost	558	811	2,042	2,229
Defined Benefit Plan, Amortization of Prior Service Cost	(29)	(41)	(91)	(93)
Defined Benefit Plan, Amortization of Net Actuarial Loss	327	56	829	756
Defined Benefit Plan, Net pension benefit cost	$ 1,019	$ 880	$ 3,255	$ 3,358