Comprehensive Income (Reclassification Out of AOCI) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	$ 56,463		$ 84,058
Tax impact	(17,189)		(33,275)
Net income	39,274		50,783		64,695
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension Benefits [Member] | Amortization Of Defined Benefit Cost Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Prior-service costs	(11)	[1],[2]	(2)	[1],[2]
Actuarial gains/(losses)	(4,819)	[1],[2]	(10,072)	[1],[2]
Income before income taxes	(4,830)	[1],[2]	(10,074)	[1],[2]
Tax impact	1,835	[1],[2]	3,828	[1],[2]
Net income	(2,995)	[1],[2]	(6,246)	[1],[2]
Reclassification out of Accumulated Other Comprehensive Income [Member] | Postretirement Costs [Member] | Amortization Of Defined Benefit Cost Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Prior-service costs	890	[1],[2]	1,525	[1],[2]
Actuarial gains/(losses)	(722)	[1],[2]	(2,228)	[1],[2]
Income before income taxes	168	[1],[2]	(703)	[1],[2]
Tax impact	(64)	[1],[2]	267	[1],[2]
Net income	$ 104	[1],[2]	$ (436)	[1],[2]

[1] Amounts in parentheses indicate losses.

[2] These accumulated other comprehensive loss components are included in the computation of net periodic pension and OPEB costs (see Note 14 - Retirement Plans for additional details).