Derivative Instruments and Hedging Activities (Narrative) (Details) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($) derivative_instrument	Sep. 30, 2020 USD ($) settled_derivative derivative_instrument	Dec. 31, 2019 USD ($) settled_derivative
Interest rate cap
Derivative [Line Items]
Interest rate swap agreements settled | settled_derivative		0	1
Interest rate derivatives
Derivative [Line Items]
Reduction in interest expense	$ 800	$ 2,400
Credit Risk Contract
Derivative [Line Items]
Derivative liability fair value gross	60,300	60,300	$ 41,600
Designated as Hedging Instrument
Derivative [Line Items]
Derivative liability fair value gross	$ 56,931	$ 56,931	40,135
Designated as Hedging Instrument | Interest rate cap
Derivative [Line Items]
Notional amount, asset			230,000
Payment received from derivative settlement			$ 200
Designated as Hedging Instrument | Interest rate derivatives
Derivative [Line Items]
Derivatives deferred effective portion of fair value change | derivative_instrument	2	2
Loss on derivative expected amount to be reclassified	$ 23,600	$ 23,600
Settled Interest Rate Swap, One | Designated as Hedging Instrument | Interest rate derivatives
Derivative [Line Items]
Derivative change in fair value recognition period		7 years 3 months 18 days
Settled Interest Rate Swap, Two | Designated as Hedging Instrument | Interest rate derivatives
Derivative [Line Items]
Derivative change in fair value recognition period		1 year