Derivative Instruments and Hedging Activities - Open Interest Rate Swap Contracts (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Cash Flow Hedging | Interest Rate Swap, May 2018 To May 2021 [Member]
Derivative [Line Items]
Notional Amounts (in U.S. dollars)		$ 25,000	$ 25,000
Net Unrealized Gain (Loss)		(200)	(100)
Cash Flow Hedging | Interest Rate Swap, September 2019 To September 2023 [Member]
Derivative [Line Items]
Notional Amounts (in U.S. dollars)		150,000	150,000
Net Unrealized Gain (Loss)		(11,300)	(7,700)
Cash Flow Hedging | Interest Rate Swap, May 2019 To May 2020 [Member] [Member]
Derivative [Line Items]
Net Unrealized Gain (Loss)			(200)
Derivative, Notional Amount1			100,000
Cash Flow Hedging | Interest Rate Swap
Derivative [Line Items]
Notional Amounts (in U.S. dollars)		575,000	275,000
Net Unrealized Gain (Loss)		(18,100)	(8,000)
Cash Flow Hedging | Interest Rate Swap, March 2020 To February 2023 [Member]
Derivative [Line Items]
Net Unrealized Gain (Loss)		(6,600)
Derivative, Notional Amount1		400,000
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Net Unrealized Gain (Loss)		(20,400)	(8,100)
Designated as Hedging Instrument [Member] | Interest Rate Swap
Derivative [Line Items]
Net Unrealized Gain (Loss)	[1]	$ (18,100)	$ (8,000)

[1] Assets are included in prepaid expenses and other and liabilities are included in other accrued expenses on the accompanying consolidated balance sheets.