Derivatives and Hedging Activities - Schedule of Interest Rate Derivatives (Details) - Designated as Hedging Instrument - Cash Flow Hedging - Swap $ in Thousands	Sep. 30, 2016 USD ($) derivative	Dec. 31, 2015 USD ($) derivative
Derivative [Line Items]
Number of Instruments (derivative) | derivative	28	43
Notional Amount | $	$ 801,492	$ 1,259,207
GBP
Derivative [Line Items]
Number of Instruments (derivative) | derivative	18	27
Notional Amount | $	$ 403,626	$ 697,925
EUR
Derivative [Line Items]
Number of Instruments (derivative) | derivative	10	16
Notional Amount | $	$ 397,866	$ 561,282