Derivatives and Hedging Activities - Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk (Details) - Designated as Hedging Instrument - Cash Flow Hedging $ in Millions	Sep. 30, 2020 USD ($) instrument	Apr. 30, 2019 USD ($) instrument
Derivatives, Fair Value [Line Items]
Notional Aggregate Principal Amount	$ 850.0
Interest rate cap contract
Derivatives, Fair Value [Line Items]
Number of Instruments | instrument	1
Notional Aggregate Principal Amount	$ 256.4	$ 500.0
Interest Cap (as a percent)	3.50%
Interest rate swap contracts
Derivatives, Fair Value [Line Items]
Number of Instruments | instrument	2	2
Notional Aggregate Principal Amount	$ 350.0	$ 350.0
Swap Rate (as a percent)	2.301%
Forward-starting interest rate swap contracts
Derivatives, Fair Value [Line Items]
Number of Instruments | instrument	2
Notional Aggregate Principal Amount	$ 500.0
Swap Rate (as a percent)	0.37%