Selected Quarterly Consolidated Financial Information (Summary Of Selected Quarterly Consolidated Financial Information) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2010		Sep. 30, 2010		Jun. 30, 2010		Mar. 31, 2010		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Interest income	$ 174,706	[1]	$ 177,027	[1]	$ 178,757	[1]	$ 178,157	[1]	$ 699,723		$ 708,647		$ 746,090
Interest expense	37,679	[1]	41,569	[1]	45,692	[1]	46,436	[1]	135,955		171,376		250,704
Net interest income	137,027	[1]	135,458	[1]	133,065	[1]	131,721	[1]	563,768	[2]	537,271	[2],[3]	495,386	[2],[3]
Provision for loan and lease losses	15,000	[1]	25,000	[1]	32,000	[1]	43,000	[1]	22,500	[2]	115,000	[2],[3]	303,000	[2],[3]
Net gain on sale of investment securities	39	[1]	1,027	[1]	4,364	[1]	4,318	[1]	3,823		9,748		(13,810)
Net impairment losses recognized in earnings			(970)	[1]	(1,188)	[1]	(3,680)	[1]			5,838		28,477
Net loss on trading securities	2,256	[1]	1,205	[1]	8,584	[1]			(1,799)		12,045
Other non-interest income	42,721	[1]	45,185	[1]	52,099	[1]	45,265	[1]	177,042	[2]	201,225	[2],[3]	184,395	[2],[3]
Litigation			2,800	[1]	19,676	[1]			(9,523)		22,476
Other non-interest expense	127,962	[1]	126,921	[1]	127,991	[1]	133,624	[1]	510,976	[2]	538,974	[2],[3]	507,394	[2],[3]
Income from continuing operations before income tax expense	39,081	[1]	27,184	[1]	17,257	[1]	1,000	[1]	207,334	[2]	84,522	[2],[3]	(130,613)	[2],[3]
Income tax expense	7,219	[1]	4,561	[1]	378	[1]	200	[1]	57,951	[2]	12,358	[2],[3]	(53,424)	[2],[3]
Income from continuing operations	31,862	[1]	22,623	[1]	16,879	[1]	800	[1]	149,383		72,164		(77,189)
Income from discontinued operations, net of tax	94	[1]							1,995		94		302
Net income	31,956	[1]	22,623	[1]	16,879	[1]	800	[1]	151,378	[2]	72,258	[2],[3]	(76,887)	[2],[3]
Less: Net (loss) income attributable to non controlling interests	(1)	[1]	(3)	[1]	7	[1]			(1)	[2]	3	[2],[3]	22	[2],[3]
Net income attributable to Webster Financial Corporation	31,957	[1]	22,626	[1]	16,872	[1]	800	[1]	151,379	[2]	72,255	[2],[3]	(76,909)	[2],[3]
Preferred stock dividends	(3,469)	[1]	(4,581)	[1]	(4,581)	[1]	(5,455)	[1]	(3,286)		(18,086)		(32,863)
Accretion of preferred stock discount	(4,141)	[1]	(327)	[1]	(327)	[1]	(2,035)	[1]
Net (loss) income available to common shareholders	24,347	[1]	17,718	[1]	11,964	[1]	(6,690)	[1]	148,093		47,339		(86,529)
Net income (loss) from continuing operations	$ 0.31	[1]	$ 0.23	[1]	$ 0.15	[1]	$ (0.09)	[1]	$ 1.67		$ 0.60	[4]	$ (1.43)	[4]
Income from discontinued operations, net of tax									$ 0.02				$ 0.01	[4]
Net income (loss) available to common shareholders	$ 0.31	[1]	$ 0.23	[1]	$ 0.15	[1]	$ (0.09)	[1]	$ 1.69		$ 0.60	[4]	$ (1.42)	[4]
Income (loss) from continuing operations	$ 0.29	[1]	$ 0.22	[1]	$ 0.14	[1]	$ (0.09)	[1]	$ 1.59		$ 0.57	[4]	$ (2.17)	[4]
Income from discontinued operations, net of tax									$ 0.02				$ 0.01	[4]
Net income (loss) available to common shareholders	$ 0.29	[1]	$ 0.22	[1]	$ 0.14	[1]	$ (0.09)	[1]	$ 1.61		$ 0.57	[4]	$ (2.16)	[4]
Parent Company [Member]
Provision for loan and lease losses									(136)		136	[5]
Net gain on sale of investment securities									374				(7,167)	[5]
Income from continuing operations before income tax expense									(29,443)		(6,970)	[5]	(13,628)	[5]
Income tax expense									(18,481)		(8,061)	[5]	(1,388)	[5]
Income from continuing operations									149,384		72,161	[5]	(77,211)	[5]
Income from discontinued operations, net of tax									$ 1,995		$ 94	[5]	$ 302	[5]

[1] Certain previously reported information has been corrected to reflect the deferrment of certain commercial loan fees. For more information refer to Note 1.

[2] Reclassified to conform to the 2011 presentation. The consumer liquidating portfolio was not established as a separate operating unit until April 2010, as part of the presentation for 2010, the consumer liquidating portfolio for the three months ended March 31, 2010 has not been reclassified to conform to the 2011 presentation. As part of the presentation for 2009, the consumer liquidating portfolio for the year ended December 31, 2009 has not been reclassified to conform to the 2011 presentation, and total assets at December 31, 2009 has not been reclassified to conform to the 2011 and 2010 presentations.

[3] Certain previously reported information has been corrected to reflect the deferment of certain commercial loan fees. For more information refer to Note 1

[4] Certain previously reported information has been corrected to reflect the deferment of certain commercial loan fees. For more information refer to Note 1.

[5] Certain previously reported information has been corrected to reflect the deferment of certain commercial loan fees.