Loans Receivable and Allowance for Loan Losses (Summary of Impaired Loans Receivable by Class) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Loans with no related allowance
Loans with no related allowance, Unpaid Principal Balance	$ 38,180	$ 39,054
Loans with no related allowance, Recorded Investment	30,540	31,410
Loans with no related allowance, Related Allowance	0	0
Loans with no related allowance, Average Recorded Investment	30,786	32,152
Loans with no related allowance, Interest Income Recognized	262	955
Loans with an allowance recorded
Loans with an allowance recorded, Unpaid Principal Balance	41,247	22,542
Loans with an allowance recorded, Recorded Investment	37,731	20,631
Loans with an allowance recorded, Related Allowance	4,548	2,690
Loans with an allowance recorded, Average Recorded Investment	40,091	21,893
Loans with an allowance recorded, Interest Income Recognized	237	801
Total impaired loans
Unpaid Principal Balance	79,427	61,596
Recorded Investment	68,271	52,041
Related Allowance	4,548	2,690
Average Recorded Investment	70,877	54,045
Interest Income Recognized	499	1,756
Mortgage Portfolio Segment [Member]
Loans with no related allowance
Loans with no related allowance, Unpaid Principal Balance	15,069	18,276
Loans with no related allowance, Recorded Investment	12,247	15,385
Loans with no related allowance, Related Allowance	0	0
Loans with no related allowance, Average Recorded Investment	12,279	15,574
Loans with no related allowance, Interest Income Recognized	135	491
Loans with an allowance recorded
Loans with an allowance recorded, Unpaid Principal Balance	13,700	14,116
Loans with an allowance recorded, Recorded Investment	12,680	13,074
Loans with an allowance recorded, Related Allowance	1,327	1,486
Loans with an allowance recorded, Average Recorded Investment	12,746	13,226
Loans with an allowance recorded, Interest Income Recognized	133	529
Total impaired loans
Unpaid Principal Balance	28,769	32,392
Recorded Investment	24,927	28,459
Related Allowance	1,327	1,486
Average Recorded Investment	25,025	28,800
Interest Income Recognized	268	1,020
Mortgage Portfolio Segment [Member] | Residential Real Estate [Member]
Loans with no related allowance
Loans with no related allowance, Unpaid Principal Balance	13,519	13,239
Loans with no related allowance, Recorded Investment	10,701	10,477
Loans with no related allowance, Related Allowance	0	0
Loans with no related allowance, Average Recorded Investment	10,733	10,552
Loans with no related allowance, Interest Income Recognized	135	479
Loans with an allowance recorded
Loans with an allowance recorded, Unpaid Principal Balance	12,642	13,052
Loans with an allowance recorded, Recorded Investment	11,622	12,010
Loans with an allowance recorded, Related Allowance	1,199	1,351
Loans with an allowance recorded, Average Recorded Investment	11,673	12,150
Loans with an allowance recorded, Interest Income Recognized	120	475
Total impaired loans
Unpaid Principal Balance	26,161	26,291
Recorded Investment	22,323	22,487
Related Allowance	1,199	1,351
Average Recorded Investment	22,406	22,702
Interest Income Recognized	255	954
Mortgage Portfolio Segment [Member] | Commercial Real Estate [Member]
Loans with no related allowance
Loans with no related allowance, Unpaid Principal Balance	1,550	5,037
Loans with no related allowance, Recorded Investment	1,546	4,908
Loans with no related allowance, Related Allowance	0	0
Loans with no related allowance, Average Recorded Investment	1,546	5,022
Loans with no related allowance, Interest Income Recognized	0	12
Loans with an allowance recorded
Loans with an allowance recorded, Unpaid Principal Balance	1,058	1,064
Loans with an allowance recorded, Recorded Investment	1,058	1,064
Loans with an allowance recorded, Related Allowance	128	135
Loans with an allowance recorded, Average Recorded Investment	1,073	1,076
Loans with an allowance recorded, Interest Income Recognized	13	54
Total impaired loans
Unpaid Principal Balance	2,608	6,101
Recorded Investment	2,604	5,972
Related Allowance	128	135
Average Recorded Investment	2,619	6,098
Interest Income Recognized	13	66
Commercial Loans [Member]
Loans with no related allowance
Loans with no related allowance, Unpaid Principal Balance	21,552	19,196
Loans with no related allowance, Recorded Investment	17,277	14,984
Loans with no related allowance, Related Allowance	0	0
Loans with no related allowance, Average Recorded Investment	17,467	15,428
Loans with no related allowance, Interest Income Recognized	109	395
Loans with an allowance recorded
Loans with an allowance recorded, Unpaid Principal Balance	26,236	7,097
Loans with an allowance recorded, Recorded Investment	23,751	6,239
Loans with an allowance recorded, Related Allowance	3,152	1,134
Loans with an allowance recorded, Average Recorded Investment	26,022	7,318
Loans with an allowance recorded, Interest Income Recognized	89	208
Total impaired loans
Unpaid Principal Balance	47,788	26,293
Recorded Investment	41,028	21,223
Related Allowance	3,152	1,134
Average Recorded Investment	43,489	22,746
Interest Income Recognized	198	603
Consumer Loans [Member]
Loans with no related allowance
Loans with no related allowance, Unpaid Principal Balance	1,559	1,582
Loans with no related allowance, Recorded Investment	1,016	1,041
Loans with no related allowance, Related Allowance	0	0
Loans with no related allowance, Average Recorded Investment	1,040	1,150
Loans with no related allowance, Interest Income Recognized	18	69
Loans with an allowance recorded
Loans with an allowance recorded, Unpaid Principal Balance	1,311	1,329
Loans with an allowance recorded, Recorded Investment	1,300	1,318
Loans with an allowance recorded, Related Allowance	69	70
Loans with an allowance recorded, Average Recorded Investment	1,323	1,349
Loans with an allowance recorded, Interest Income Recognized	15	64
Total impaired loans
Unpaid Principal Balance	2,870	2,911
Recorded Investment	2,316	2,359
Related Allowance	69	70
Average Recorded Investment	2,363	2,499
Interest Income Recognized	$ 33	$ 133