Derivative Financial Instruments (Interest Rate Swaps And Caps Not Designated For Hedge Accounting) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Customer Position Commercial Loan Interest Rate Swaps One [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Not designated for hedge accounting, Consolidated Balance Sheet Location	Other assets
Not designated for hedge accounting, Number of Instruments	127	98
Not designated for hedge accounting, Notional Amount	$ 615,773	$ 447,689
Not designated for hedge accounting, Estimated Fair Value	45,140	33,890
Customer Position Commercial Loan Interest Rate Swaps Two [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Not designated for hedge accounting, Consolidated Balance Sheet Location	Other liabilities
Not designated for hedge accounting, Number of Instruments	0	2
Not designated for hedge accounting, Notional Amount		30,542
Not designated for hedge accounting, Estimated Fair Value		(990)
Customer Position Commercial Loan Interest Rate Swaps With Floors [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Not designated for hedge accounting, Consolidated Balance Sheet Location	Other assets
Not designated for hedge accounting, Number of Instruments	12	12
Not designated for hedge accounting, Notional Amount	25,217	28,342
Not designated for hedge accounting, Estimated Fair Value	1,994	1,060
Customer Position Commercial Loan Interest Rate Caps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Not designated for hedge accounting, Consolidated Balance Sheet Location	Other liabilities
Not designated for hedge accounting, Number of Instruments	13	5
Not designated for hedge accounting, Notional Amount	119,186	19,164
Not designated for hedge accounting, Estimated Fair Value	(160)	(83)
Webster Position Commercial Loan Interest Rate Swaps One [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Not designated for hedge accounting, Consolidated Balance Sheet Location	Other liabilities
Not designated for hedge accounting, Number of Instruments	119	92
Not designated for hedge accounting, Notional Amount	595,542	429,290
Not designated for hedge accounting, Estimated Fair Value	(40,269)	(31,394)
Webster Position Commercial Loan Interest Rate Swaps Two [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Not designated for hedge accounting, Consolidated Balance Sheet Location	Other liabilities
Not designated for hedge accounting, Number of Instruments	4	7
Not designated for hedge accounting, Notional Amount	20,180	48,895
Not designated for hedge accounting, Estimated Fair Value	13	1,362
Webster Position Commercial Loan Interest Rate Swaps With Floors One [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Not designated for hedge accounting, Consolidated Balance Sheet Location	Other liabilities
Not designated for hedge accounting, Number of Instruments	12	12
Not designated for hedge accounting, Notional Amount	25,217	28,342
Not designated for hedge accounting, Estimated Fair Value	$ (1,597)	$ (625)