Derivatives and Hedging Activity (Details) - 9 months ended Sep. 30, 2015 € in Thousands, £ in Thousands, SEK in Thousands, NOK in Thousands, DKK in Thousands, $ in Thousands	SEK instrument item	NOK instrument item	GBP (£) instrument item	DKK instrument item	EUR (€) instrument item	USD ($) instrument item
Derivatives
Number of contracts	247	247	247	247	247	247
Foreign exchange contracts | GBP | Sell
Derivatives
Number of contracts	63	63	63	63	63	63
Aggregate notional amount | £			£ 257,203
Foreign exchange contracts | EUR | Sell
Derivatives
Number of contracts	87	87	87	87	87	87
Aggregate notional amount | €					€ 352,420
Foreign exchange contracts | EUR | Sell | Ireland Portfolio
Derivatives
Number of contracts	59	59	59	59	59	59
Aggregate notional amount | €					€ 259,700
Foreign exchange contracts | SEK | Buy
Derivatives
Number of contracts	1	1	1	1	1	1
Aggregate notional amount | SEK	SEK 4,083
Foreign exchange contracts | SEK | Sell
Derivatives
Number of contracts	2	2	2	2	2	2
Aggregate notional amount | SEK	SEK 19,197
Foreign exchange contracts | NOK | Sell
Derivatives
Number of contracts	1	1	1	1	1	1
Aggregate notional amount | NOK		NOK 1,218
Foreign exchange contracts | DKK | Sell
Derivatives
Number of contracts	1	1	1	1	1	1
Aggregate notional amount | DKK				DKK 3,200
Interest rate swaps | Paying fixed rates
Derivatives
Number of contracts	73	73	73	73	73	73
Aggregate notional amount | $						$ 513,218
Interest rate swaps | Receiving fixed rates
Derivatives
Number of contracts	4	4	4	4	4	4
Aggregate notional amount | $						$ 14,300
Interest rate swaps | Derivatives designated as hedging instruments
Derivatives
Number of contracts | instrument	8	8	8	8	8	8
Aggregate notional amount | $						$ 87,500
Fixed monthly coupons at fixed rate, low end of range (as a percent)	0.56%	0.56%	0.56%	0.56%	0.56%	0.56%
Fixed monthly coupons at fixed rate, high end of range (as a percent)	2.23%	2.23%	2.23%	2.23%	2.23%	2.23%
Amount expected to be reclassified from other comprehensive income to interest expense over the next twelve months | $						$ 400
Hedging period for covering exposure to the variability in future cash flows	68 months
Interest rate caps | EUR
Derivatives
Number of contracts	2	2	2	2	2	2
Aggregate notional amount | €					€ 294,000
Interest rate caps | USD
Derivatives
Number of contracts	2	2	2	2	2	2
Aggregate notional amount | $						$ 17,835
Credit index instruments
Derivatives
Number of contracts	11	11	11	11	11	11
Aggregate notional amount | $						$ 40,000