Derivatives and Hedging Activities - Narrative (Details) lb in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2016 USD ($) lb	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) lb	Dec. 31, 2015 USD ($)	Jun. 30, 2016 USD ($)
Fair value of derivatives
Total asset derivatives on a gross basis	$ 8,300,000		$ 8,300,000
Total liability derivatives on a gross basis	21,700,000		21,700,000
Cash collateral held by counterparties	$ 0		0		$ 0
Net derivative losses included in AOCI expected to be reclassified into earnings			$ 10,300,000
Cash flow hedges | Commodity contracts
Fair value of derivatives
Amounts of raw materials to be purchased from forward contracts (in pounds) | lb	19.3		19.3
Cash flow hedges | Interest rate swaps
Fair value of derivatives
Net gains recorded as a reduction to interest expense	$ 100,000	$ 100,000	$ 200,000	$ 200,000
Fair value hedging | Interest rate swaps
Fair value of derivatives
Net gains recorded as a reduction to interest expense	500,000	$ 600,000	900,000	$ 1,300,000
Total notional amounts of interest rate contracts	$ 150,000,000		$ 150,000,000		$ 150,000,000