Derivative Financial Instruments and Hedging Activities - Derivative Instruments Fair Value Table (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) derivative	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) derivative	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Derivatives, Fair Value
Derivatives expected to be reclassified in the next 12 months	$ 6,100,000		$ 6,100,000
Asset Derivatives	0		0		$ 3,011,000
Liability Derivatives	16,697,000		16,697,000		29,000
Fair value of derivatives in net liability position, including accrued interest, excluding nonperformance risk adjustment	$ 17,000,000.0		$ 17,000,000.0
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps
Derivatives, Fair Value
Number of instruments | derivative	7		7
Notional amount	$ 500,000,000		$ 500,000,000
Gain (loss) recognized in OCI	521,000	$ 2,559,000	(25,932,000)	$ 2,508,000
Gain (loss) reclassified from accumulated OCI into income	(1,533,000)	$ 269,000	(2,260,000)	$ 989,000
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Receivables and other assets
Derivatives, Fair Value
Asset Derivatives	0		0		3,011,000
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Derivative financial instruments
Derivatives, Fair Value
Liability Derivatives	$ 16,697,000		$ 16,697,000		$ 29,000