Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Comprehensive income
Net earnings	$ 25,256us-gaap_NetIncomeLoss	$ 18,486us-gaap_NetIncomeLoss	$ 94,212us-gaap_NetIncomeLoss	$ 73,096us-gaap_NetIncomeLoss
Other comprehensive income, net of income taxes
Pension and other postretirement benefit plans activity	42	269	126	927
Unrealized loss on interest rate swaps	(1,753)	0	(2,252)	0
Other comprehensive income (loss), net of income taxes	(1,711)	269	(2,126)	927
Comprehensive income	$ 23,545us-gaap_ComprehensiveIncomeNetOfTax	$ 18,755us-gaap_ComprehensiveIncomeNetOfTax	$ 92,086us-gaap_ComprehensiveIncomeNetOfTax	$ 74,023us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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