Loans and Leases, Net (Impaired Loans And Leases By Class) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Unpaid Principal Balance	$ 544,854	$ 610,985
Total Recorded Investment	495,276	569,097
Related Valuation Allowance	46,605	35,997
1-4 Family [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	133,123	117,997	[1]
Total Recorded Investment	124,461	112,402	[1]
Related Valuation Allowance	16,611	11,358	[1]
Permanent-NCLC [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	12,005	10,789	[1]
Total Recorded Investment	10,718	10,111	[1]
Related Valuation Allowance	2,747	2,204	[1]
Construction [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	129
Total Recorded Investment	132
Related Valuation Allowance	9
Liquidating Portfolio-Construction Loans [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance		165	[1]
Total Recorded Investment		1	[1]
Home Equity Loans [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	35,285	31,174	[1]
Total Recorded Investment	31,153	26,664	[1]
Related Valuation Allowance	4,116	2,577	[1]
Liquidating Portfolio-Home Equity Loans [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	7,277	9,707	[1]
Total Recorded Investment	5,469	5,485	[1]
Related Valuation Allowance	1,050	888	[1]
Other Consumer [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	7	8	[1]
Total Recorded Investment	7	8	[1]
Related Valuation Allowance	1	1	[1]
Commercial Non-Mortgage [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	118,293	140,284
Total Recorded Investment	105,359	134,944
Related Valuation Allowance	12,996	10,589
Asset-Based Loans [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	7,814	15,731
Total Recorded Investment	1,859	13,807
Related Valuation Allowance		133
Commercial Real Estate [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	195,838	183,521
Total Recorded Investment	189,575	180,137
Related Valuation Allowance	8,514	5,054
Commercial Construction [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	7,347	39,468
Total Recorded Investment	7,373	36,296
Related Valuation Allowance	557	2,015
Residential Development [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	16,495	33,082
Total Recorded Investment	15,902	31,763
Related Valuation Allowance		1,097
Equipment Financing [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	11,241	29,059
Total Recorded Investment	3,268	17,479
Related Valuation Allowance	4	81
Total Residential [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	145,257	128,951
Total Recorded Investment	135,311	122,514
Related Valuation Allowance	19,367	13,562
Total Consumer [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	42,569	40,889
Total Recorded Investment	36,629	32,157
Related Valuation Allowance	5,167	3,466
Total Commercial [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	126,107	156,015
Total Recorded Investment	107,218	148,751
Related Valuation Allowance	12,996	10,722
Total Commercial Real Estate [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	219,680	256,071
Total Recorded Investment	212,850	248,196
Related Valuation Allowance	9,071	8,166
Total Equipment Financing [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance	11,241	29,059
Total Recorded Investment	3,268	17,479
Related Valuation Allowance	4	81
Loans And Leases With No Allowance [Member]
Debt Instrument [Line Items]
Total Recorded Investment	156,344	206,055
Loans And Leases With No Allowance [Member] | 1-4 Family [Member]
Debt Instrument [Line Items]
Total Recorded Investment		146	[1]
Loans And Leases With No Allowance [Member] | Liquidating Portfolio-Construction Loans [Member]
Debt Instrument [Line Items]
Total Recorded Investment		1	[1]
Loans And Leases With No Allowance [Member] | Home Equity Loans [Member]
Debt Instrument [Line Items]
Total Recorded Investment	4	95	[1]
Loans And Leases With No Allowance [Member] | Liquidating Portfolio-Home Equity Loans [Member]
Debt Instrument [Line Items]
Total Recorded Investment	3	39	[1]
Loans And Leases With No Allowance [Member] | Commercial Non-Mortgage [Member]
Debt Instrument [Line Items]
Total Recorded Investment	30,207	52,772
Loans And Leases With No Allowance [Member] | Asset-Based Loans [Member]
Debt Instrument [Line Items]
Total Recorded Investment	1,859	10,382
Loans And Leases With No Allowance [Member] | Commercial Real Estate [Member]
Debt Instrument [Line Items]
Total Recorded Investment	105,618	88,638
Loans And Leases With No Allowance [Member] | Commercial Construction [Member]
Debt Instrument [Line Items]
Total Recorded Investment		17,823
Loans And Leases With No Allowance [Member] | Residential Development [Member]
Debt Instrument [Line Items]
Total Recorded Investment	15,902	21,139
Loans And Leases With No Allowance [Member] | Equipment Financing [Member]
Debt Instrument [Line Items]
Total Recorded Investment	2,751	15,020
Loans And Leases With No Allowance [Member] | Total Residential [Member]
Debt Instrument [Line Items]
Total Recorded Investment		147
Loans And Leases With No Allowance [Member] | Total Consumer [Member]
Debt Instrument [Line Items]
Total Recorded Investment	7	134
Loans And Leases With No Allowance [Member] | Total Commercial [Member]
Debt Instrument [Line Items]
Total Recorded Investment	32,066	63,154
Loans And Leases With No Allowance [Member] | Total Commercial Real Estate [Member]
Debt Instrument [Line Items]
Total Recorded Investment	121,520	127,600
Loans And Leases With No Allowance [Member] | Total Equipment Financing [Member]
Debt Instrument [Line Items]
Total Recorded Investment	2,751	15,020
Loans And Leases With Specific Allowance [Member]
Debt Instrument [Line Items]
Total Recorded Investment	338,932	363,042
Loans And Leases With Specific Allowance [Member] | 1-4 Family [Member]
Debt Instrument [Line Items]
Total Recorded Investment	124,461	112,256	[1]
Loans And Leases With Specific Allowance [Member] | Permanent-NCLC [Member]
Debt Instrument [Line Items]
Total Recorded Investment	10,718	10,111	[1]
Loans And Leases With Specific Allowance [Member] | Construction [Member]
Debt Instrument [Line Items]
Total Recorded Investment	132
Loans And Leases With Specific Allowance [Member] | Home Equity Loans [Member]
Debt Instrument [Line Items]
Total Recorded Investment	31,149	26,569	[1]
Loans And Leases With Specific Allowance [Member] | Liquidating Portfolio-Home Equity Loans [Member]
Debt Instrument [Line Items]
Total Recorded Investment	5,466	5,446	[1]
Loans And Leases With Specific Allowance [Member] | Other Consumer [Member]
Debt Instrument [Line Items]
Total Recorded Investment	7	8	[1]
Loans And Leases With Specific Allowance [Member] | Commercial Non-Mortgage [Member]
Debt Instrument [Line Items]
Total Recorded Investment	75,152	82,172
Loans And Leases With Specific Allowance [Member] | Asset-Based Loans [Member]
Debt Instrument [Line Items]
Total Recorded Investment		3,425
Loans And Leases With Specific Allowance [Member] | Commercial Real Estate [Member]
Debt Instrument [Line Items]
Total Recorded Investment	83,957	91,499
Loans And Leases With Specific Allowance [Member] | Commercial Construction [Member]
Debt Instrument [Line Items]
Total Recorded Investment	7,373	18,473
Loans And Leases With Specific Allowance [Member] | Residential Development [Member]
Debt Instrument [Line Items]
Total Recorded Investment		10,624
Loans And Leases With Specific Allowance [Member] | Equipment Financing [Member]
Debt Instrument [Line Items]
Total Recorded Investment	517	2,459
Loans And Leases With Specific Allowance [Member] | Total Residential [Member]
Debt Instrument [Line Items]
Total Recorded Investment	135,311	122,367
Loans And Leases With Specific Allowance [Member] | Total Consumer [Member]
Debt Instrument [Line Items]
Total Recorded Investment	36,622	32,023
Loans And Leases With Specific Allowance [Member] | Total Commercial [Member]
Debt Instrument [Line Items]
Total Recorded Investment	75,152	85,597
Loans And Leases With Specific Allowance [Member] | Total Commercial Real Estate [Member]
Debt Instrument [Line Items]
Total Recorded Investment	91,330	120,596
Loans And Leases With Specific Allowance [Member] | Total Equipment Financing [Member]
Debt Instrument [Line Items]
Total Recorded Investment	$ 517	$ 2,459

[1] As permitted in accordance with applicable accounting guidance, non-TDR residential and consumer loans that are collectively evaluated for impairment on a pooled basis have been removed from the "Residential" and "Consumer" data with respect to impaired loans and leases with no valuation allowance as originally presented at December 31, 2010. Management believes that these changes are immaterial to Webster's financial statements and align reporting of such data more closely with peer banks.