Loans Receivable (Accretable yield and non-accretable discount activity) (Details) - Acquired under ASC 310-30 Non-Covered Loans [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 354,701	$ 361,688	$ 445,946
Accretion Accretable	58,957	75,637	112,113
Change in expected cash flow	22,565	15,267	8,531
Transfer from (to) non-accretable discount	(9,396)	53,383	19,324
Balance at end of period	308,913	354,701	361,688
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Non Accretable Discount Movement Schedule [Roll Forward]
Balance at beginning of period	363,107	434,190	456,627
Change in actual and expected losses	(20,072)	(17,700)	(3,113)
Transfer (to) from accretable yield	9,396	(53,383)	(19,324)
Balance at end of period	352,431	363,107	434,190
Mortgage Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	292,115	268,794	298,364
Accretion Accretable	30,205	32,834	34,842
Change in expected cash flow	2	(1)	0
Transfer from (to) non-accretable discount	(3,414)	56,156	5,272
Balance at end of period	258,498	292,115	268,794
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Non Accretable Discount Movement Schedule [Roll Forward]
Balance at beginning of period	305,615	374,772	389,839
Change in actual and expected losses	(9,528)	(13,001)	(9,795)
Transfer (to) from accretable yield	3,414	(56,156)	(5,272)
Balance at end of period	299,501	305,615	374,772
Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	50,366	65,026	87,025
Accretion Accretable	20,572	26,254	49,429
Change in expected cash flow	22,250	14,259	8,532
Transfer from (to) non-accretable discount	(5,280)	(2,665)	18,898
Balance at end of period	46,764	50,366	65,026
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Non Accretable Discount Movement Schedule [Roll Forward]
Balance at beginning of period	16,965	18,545	26,555
Change in actual and expected losses	(11,649)	(4,245)	10,888
Transfer (to) from accretable yield	5,280	2,665	(18,898)
Balance at end of period	10,596	16,965	18,545
Auto Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	8,538	21,578	53,998
Accretion Accretable	6,339	13,567	23,463
Change in expected cash flow	170	1,251	0
Transfer from (to) non-accretable discount	397	(724)	(8,957)
Balance at end of period	2,766	8,538	21,578
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Non Accretable Discount Movement Schedule [Roll Forward]
Balance at beginning of period	22,407	22,039	16,215
Change in actual and expected losses	1,040	(356)	(3,133)
Transfer (to) from accretable yield	(397)	724	8,957
Balance at end of period	23,050	22,407	22,039
Consumer Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	3,682	6,290	6,559
Accretion Accretable	1,841	2,982	4,379
Change in expected cash flow	143	(242)	(1)
Transfer from (to) non-accretable discount	(1,099)	616	4,111
Balance at end of period	885	3,682	6,290
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Non Accretable Discount Movement Schedule [Roll Forward]
Balance at beginning of period	18,120	18,834	24,018
Change in actual and expected losses	65	(98)	(1,073)
Transfer (to) from accretable yield	1,099	(616)	(4,111)
Balance at end of period	$ 19,284	$ 18,120	$ 18,834