Loans, Allowance for Loan Losses and Credit Quality (Impaired Loans by Portfolio) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Mar. 31, 2019
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 980	$ 1,104
Related Allowance	980
Impaired Financing Receivable, Recorded Investment, Total	49,628
Impaired Financing Receivable, Unpaid Principal Balance	68,140
WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	39,242
Unpaid Principal Balance	56,605
Related Allowance	0
WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	10,386
Unpaid Principal Balance	11,535
Commercial and Industrial [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	126	58
Commercial and Industrial [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	23,786
Unpaid Principal Balance	34,970
Related Allowance	0
Commercial and Industrial [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	670
Unpaid Principal Balance	670
Commercial Real Estate [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	48	75
Commercial Real Estate [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	6,213
Unpaid Principal Balance	12,101
Related Allowance	0
Commercial Real Estate [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	2,124
Unpaid Principal Balance	2,124
Construction Loans [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		0
Small Business [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	8	1
Small Business [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	469
Unpaid Principal Balance	484
Related Allowance	0
Small Business [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	68
Unpaid Principal Balance	105
Residential Real Estate [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	637	802
Residential Real Estate [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	4,976
Unpaid Principal Balance	5,123
Related Allowance	0
Residential Real Estate [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	6,252
Unpaid Principal Balance	7,163
Consumer Home Equity [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	156	161
Consumer Home Equity [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	3,764
Unpaid Principal Balance	3,893
Related Allowance	0
Consumer Home Equity [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	1,184
Unpaid Principal Balance	1,382
Consumer - Other [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	5	$ 7
Consumer - Other [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	34
Unpaid Principal Balance	34
Related Allowance	0
Consumer - Other [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	88
Unpaid Principal Balance	$ 91

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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-Publisher FASB
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