Retirement Benefits - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Pension Plans, Defined Benefit
Defined Benefit Plans Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 24,935	$ 24,839	$ 74,621	$ 79,856
Defined Benefit Plan, Interest Cost	48,034	43,329	143,043	131,322
Defined Benefit Plan, Expected Return on Plan Assets	(56,657)	(52,863)	(169,619)	(158,279)
Defined Benefit Plan, Amortization of Prior Service Cost	2,949	3,618	8,843	10,846
Defined Benefit Plan, Amortization of Net Actuarial Loss	39,914	50,347	119,593	150,495
Defined Benefit Plan, Amortization of initial net obligations (assets)	5	6	15	18
Defined Benefit Plan, Net pension benefit cost	59,180	69,276	176,496	214,258
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plans Disclosure [Line Items]
Defined Benefit Plan, Service Cost	54	255	466	619
Defined Benefit Plan, Interest Cost	811	380	2,229	2,120
Defined Benefit Plan, Amortization of Prior Service Cost	(41)	(55)	(93)	(78)
Defined Benefit Plan, Amortization of Net Actuarial Loss	56	781	756	1,037
Defined Benefit Plan, Net pension benefit cost	$ 880	$ 1,361	$ 3,358	$ 3,698