Derivative Financial Instruments and Hedging Activities - Derivative Instruments Fair Value Table (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) derivative	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) derivative	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Derivatives, Fair Value
Derivatives expected to be reclassified in the next 12 months	$ 6,500,000		$ 6,500,000
Asset Derivatives	124,000		124,000		$ 3,011,000
Liability Derivatives	22,796,000		22,796,000		29,000
Fair value of derivatives in net liability position, including accrued interest, excluding nonperformance risk adjustment	$ 23,100,000		$ 23,100,000
Cash Flow Hedging | Forward Starts
Derivatives, Fair Value
Number of interest rate instruments | derivative	2		2
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps
Derivatives, Fair Value
Number of instruments | derivative	9		9
Notional amount	$ 725,000,000		$ 725,000,000
Gain (Loss) Recognized in OCI on Derivative	(4,300,000)	$ (30,000)	(26,453,000)	$ (51,000)
Gain (Loss) Reclassified from Accumulated OCI into Income	(1,072,000)	$ 351,000	(727,000)	$ 720,000
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Receivables and other assets
Derivatives, Fair Value
Asset Derivatives	124,000		124,000		3,011,000
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Derivative financial instruments
Derivatives, Fair Value
Liability Derivatives	$ 22,796,000		$ 22,796,000		$ 29,000