Derivatives and Hedging Activities - Schedule of Interest Rate Derivatives (Details) - Designated as Hedging Instrument - Cash Flow Hedging - Swap $ in Thousands	Jun. 30, 2020 USD ($) derivative	Dec. 31, 2019 USD ($) derivative
Derivative [Line Items]
Number of Instruments (derivative) | derivative	80	68
Notional Amount | $	$ 1,009,236	$ 962,436
GBP
Derivative [Line Items]
Number of Instruments (derivative) | derivative	49	49
Notional Amount | $	$ 272,017	$ 290,965
EUR
Derivative [Line Items]
Number of Instruments (derivative) | derivative	22	16
Notional Amount | $	$ 587,219	$ 521,471
USD
Derivative [Line Items]
Number of Instruments (derivative) | derivative	9	3
Notional Amount | $	$ 150,000	$ 150,000