Derivatives and Hedging Activities - Narrative (Details) lb in Millions	3 Months Ended			6 Months Ended
	Dec. 31, 2020 USD ($) lb	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) lb	Dec. 31, 2019 USD ($)	Jun. 30, 2020 USD ($)
Fair value of derivatives
Total asset derivatives	$ 16,800,000			$ 16,800,000
Total liability derivatives	11,700,000			11,700,000
Cash collateral held by counterparties	$ 0			0		$ 0
Net derivative gains included in AOCI expected to be reclassified into earnings				2,200,000
Interest Rate Swaps
Fair value of derivatives
Derivative, gain on derivative				$ 2,300,000
Cash flow hedges | Commodity contracts
Fair value of derivatives
Amounts of raw materials to be purchased from forward contracts (in pounds) | lb	9.0			9.0
Fair value hedging | Interest Rate Swaps
Fair value of derivatives
Derivative, gain on derivative		$ 2,300,000
Total notional amounts of interest rate contracts	$ 0.0			$ 0.0		$ 150,000,000.0
Interest expense | Cash flow hedges | Interest Rate Swaps
Fair value of derivatives
Interest rate swaps net gains (losses)	100,000		$ 100,000	200,000	$ 200,000
Interest expense | Fair value hedging | Interest Rate Swaps
Fair value of derivatives
Interest rate swaps net gains (losses)	$ 0		$ (100,000)	$ (400,000)	$ (100,000)