Retirement Benefits (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Pension Plans, Defined Benefit
Defined Benefit Plans Disclosure
Defined Benefit Plan, Service Cost	$ 24,583	$ 22,457	$ 49,657	$ 49,686
Defined Benefit Plan, Interest Cost	44,305	47,465	90,798	95,009
Defined Benefit Plan, Expected Return on Plan Assets	(54,961)	(56,574)	(110,189)	(112,962)
Defined Benefit Plan, Amortization of Prior Service Cost	1,927	2,204	4,597	5,894
Defined Benefit Plan, Amortization of Net Actuarial Loss	37,297	40,261	76,725	79,679
Defined Benefit Plan, Amortization of initial net obligations (assets)	4	5	9	10
Defined Benefit Plan, Net pension benefit cost	53,155	55,818	111,597	117,316
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plans Disclosure
Defined Benefit Plan, Service Cost	156	206	312	412
Defined Benefit Plan, Interest Cost	742	709	1,484	1,418
Defined Benefit Plan, Amortization of Prior Service Cost	(31)	(26)	(62)	(52)
Defined Benefit Plan, Amortization of Net Actuarial Loss	251	350	502	700
Defined Benefit Plan, Net pension benefit cost	$ 1,118	$ 1,239	$ 2,236	$ 2,478