Earnings Per Common Share (Earnings Per Share Basic And Diluted) (Details) (USD $) In Thousands, except 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
Earnings Per Share Basic And Diluted By Common Class [Line Items]
Net income (loss) from continuing operations available to common shareholders									$ 149,383	[1]	$ 72,164	[1],[2]	$ (77,189)	[1],[2]
Net income (loss) attributable to Webster Financial Corporation	31,957	[3]	22,626	[3]	16,872	[3]	800	[3]	151,379	[1]	72,255	[1],[2]	(76,909)	[1],[2]
Add dividends paid to common shareholders									13,978		3,133		2,443
Less income allocated to participating securities									(666)		(233)	[4]
Net income (loss) available to common shareholders	24,347	[3]	17,718	[3]	11,964	[3]	(6,690)	[3]	148,093		47,339		(86,529)
Net income from discontinued operations available to common shareholders									1,995		94	[4]	302	[4]
Weighted average common shares outstanding - basic									87,007		78,175	[4]	60,943	[4]
Stock options and Restricted Stock									368		264	[4]
Warrants									4,313		3,733	[4]
Series A Preferred Stock													2,973	[4]
Weighted average common shares outstanding - diluted									91,688		82,172	[4]	63,916	[4]
Earnings from continuing operations per common share, Basic	$ 0.31	[3]	$ 0.23	[3]	$ 0.15	[3]	$ (0.09)	[3]	$ 1.67		$ 0.60	[4]	$ (1.43)	[4]
Earnings from continuing operations per common share, Diluted	$ 0.29	[3]	$ 0.22	[3]	$ 0.14	[3]	$ (0.09)	[3]	$ 1.59		$ 0.57	[4]	$ (2.17)	[4]
Earnings from discontinued operations per common share, Basic									$ 0.02				$ 0.01	[4]
Earnings from discontinued operations per common share, Diluted									$ 0.02				$ 0.01	[4]
Earnings (loss) per common share, Basic	$ 0.31	[3]	$ 0.23	[3]	$ 0.15	[3]	$ (0.09)	[3]	$ 1.69		$ 0.60	[4]	$ (1.42)	[4]
Earnings (loss) per common share, Diluted	$ 0.29	[3]	$ 0.22	[3]	$ 0.14	[3]	$ (0.09)	[3]	$ 1.61		$ 0.57	[4]	$ (2.16)	[4]
Parent Company [Member]
Earnings Per Share Basic And Diluted By Common Class [Line Items]
Add dividends paid to common shareholders									13,978		3,133	[5]	2,443	[5]
Earnings Per Share, Basic [Member]
Earnings Per Share Basic And Diluted By Common Class [Line Items]
Net income (loss) from continuing operations available to common shareholders									146,098		47,245	[4]	(86,831)	[4]
Less dividends declared or accrued Common shareholders									(13,908)		(3,117)	[4]	(2,421)	[4]
Less dividends declared or accrued Participating shares									(70)		(16)	[4]	(22)	[4]
Net income (loss) attributable to Webster Financial Corporation									132,120		44,112	[4]	(89,274)	[4]
Add dividends paid to common shareholders									13,908		3,117	[4]	2,421	[4]
Net income (loss) available to common shareholders									145,362		46,996	[4]	(86,853)	[4]
Earnings Per Share, Diluted [Member]
Earnings Per Share Basic And Diluted By Common Class [Line Items]
Net income (loss) from continuing operations available to common shareholders									146,098		47,245	[4]	(86,831)	[4]
Less dividends declared or accrued Common shareholders									(13,908)		(3,117)	[4]	(2,421)	[4]
Less dividends declared or accrued Participating shares									(70)		(16)	[4]	(22)	[4]
Net income (loss) attributable to Webster Financial Corporation									132,120		44,112	[4]	(89,274)	[4]
Add dividends paid to common shareholders									13,908		3,117	[4]	2,421	[4]
Less income allocated to participating securities									(666)		(233)	[4]
Gain on conversion of Series A Preferred Stock													(58,792)	[4]
Net income allocated to common shareholders									145,362		46,996	[4]	(138,484)	[4]
Earnings Per Share, Diluted [Member] | Series A Preferred Stock [Member]
Earnings Per Share Basic And Diluted By Common Class [Line Items]
Add dividends paid on converted shares of Series A Preferred Stock													$ 7,161	[4]

[1] 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.

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

[3] Certain previously reported information has been corrected to reflect the deferrment 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.