Shareholders' Equity (Details) (USD $)	0 Months Ended				1 Months Ended	12 Months Ended			0 Months Ended		12 Months Ended			3 Months Ended		12 Months Ended				0 Months Ended	12 Months Ended		0 Months Ended						0 Months Ended			0 Months Ended		12 Months Ended		0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended			0 Months Ended		12 Months Ended
	Jun. 08, 2011	Dec. 29, 2010	Mar. 03, 2010	Nov. 21, 2008	Jun. 30, 2008	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009	Dec. 30, 2009 Warburg Pincus [Member]	Dec. 10, 2009 Warburg Pincus [Member]	Dec. 31, 2011 Warburg Pincus [Member]	Dec. 31, 2009 Warburg Pincus [Member]	Jul. 27, 2009 Warburg Pincus [Member]	Jun. 30, 2011 Common Stock [Member]	Mar. 31, 2011 Common Stock [Member]	Dec. 31, 2011 Common Stock [Member]	Dec. 31, 2010 Common Stock [Member]	Dec. 27, 2010 Common Stock [Member]	Dec. 27, 2010 Common Stock [Member] Warburg Pincus [Member]	Jun. 08, 2011 Capital Purchase Program [Member]	Dec. 31, 2011 Capital Purchase Program [Member]	Nov. 21, 2008 Capital Purchase Program [Member]	Dec. 16, 2009 Exchange Offer [Member]	May 28, 2009 Exchange Offer [Member]	Dec. 31, 2010 Thrift Bad Debt Reserves [Member]	Dec. 31, 2009 Thrift Bad Debt Reserves [Member]	Nov. 21, 2008 Fixed Rate Cumulative Perpetual Preferred Stock, Series B [Member]	Jun. 30, 2008 Non-Cumulative Perpetual Convertible Preferred Stock, Series A [Member]	Feb. 26, 2010 Series B Cumulative Redeemable Preferred Stock [Member]	Oct. 13, 2010 Series B Cumulative Redeemable Preferred Stock [Member]	Mar. 03, 2010 Series B Cumulative Redeemable Preferred Stock [Member]	Dec. 16, 2009 Series A Preferred Stock [Member]	May 28, 2009 Series A Preferred Stock [Member]	Dec. 31, 2011 Series A Preferred Stock [Member]	Dec. 31, 2010 Series A Preferred Stock [Member]	Dec. 18, 2009 Series A Preferred Stock [Member] Warburg Pincus [Member]	Dec. 31, 2011 Series D Preferred Stock [Member]	Dec. 03, 2010 IPO [Member] Warburg Pincus [Member]	Dec. 27, 2010 IPO [Member] Common Stock [Member]	Dec. 31, 2011 First Closing [Member] Warburg Pincus [Member]	Dec. 31, 2011 First Closing [Member] Series C Preferred Stock [Member] Warburg Pincus [Member]	Dec. 31, 2011 First Closing [Member] Series D Preferred Stock [Member] Warburg Pincus [Member]	Oct. 15, 2009 Second Closing [Member] Warburg Pincus [Member]	Oct. 15, 2009 Second Closing [Member] Series C Preferred Stock [Member] Warburg Pincus [Member]	Dec. 31, 2011 First Five Years [Member]	Dec. 31, 2011 After Five Years [Member]
Class of Stock [Line Items]
Common stock repurchased																86,835	92,582
Average cost of common shares repurchased																$ 19.27	$ 17.87																						$ 18.00
Shares authorized for repurchase under share repurchase program																	2,111,200
Public offering of common stock																																							6,630,000
Total number of shares sold						90,709,350	90,688,879		610,072									8,699,848	2,069,848					6,030,000														2,069,848		4,000,000			3,000,000
Preferred shares issued																											400,000	225,000						28,939	28,939	1,940,000								44,570
Value of preferred stock per share						$ 0.01	$ 0.01																				$ 0.01	$ 0.01				$ 0.01
Proceeds to redeem remaining preferred shares under capital purchase program																		$ 200,000,000
Dividends paid on common stock, per share														$ 0.05	$ 0.01
Liquidation preference of preference stock per share																											$ 1,000	$ 1,000
Warrant to purchase																						3,282,276
Warrant, par value																				$ 0.01		$ 0.01
Warrant initial exercise price				$ 18.28																	$ 18.28
Warrants aggregate purchase price				400,000,000
Allocated to the preferred stock, warrant issued				391,300,000
Allocated to the Additional paid-in-capital, warrant issued				8,700,000
Preferred stock, percentage of dividend					8.50%																													8.50%											5.00%	9.00%
Class of warrant, exercisable period, in years						10
Repurchase occurred, date			Mar. 03, 2010
Stock repurchase program, authorized amount																													100,000,000
Acceleration of unamortized discount																														1,400,000	1,600,000
Repurchase of series B preferred stock		201,200,000
Accrued and unpaid dividends		1,200,000
Repurchase of the Series B Preferred Stock		153,000,000					400,000,000
Private placement of common stock to affiliates		8,699,848
Number of warrants issued																				3,282,276
Warrants right to purchase common stock shares, number	1
Common stock, par value						$ 0.01	$ 0.01																	$ 0.01
Investment warrants expiration date																				Nov. 21, 2018
Payments for repurchase of warrants						(16,285,000)															14,400,000
Number of warrants repurchased						272,643															2,282,276
Warrants and rights outstanding																					727,357
Number of preferred shares converted at the option of the holder						36.8046
Closing price of common stock						On or after June 15, 2013, if the closing price of Webster's common stock exceeds 130% of the then-applicable conversion price for 20 trading days during any 30 consecutive trading day period, including the last trading day of such period
Issuance of common stock for exchange of junior subordinated debentures, shares																								35.8046
Shares accepted the exchange offer																																	168,500
Common stock, Fair value																								43,700,000
Proceeds from issuance of common stock						689,000	118,359,000	1,031,000																59,000,000
Number of Series A and Series C Preferred Shares converted										4,500,000																						1,940,000				27,461
Value of warrants converted to equity											38,700,000
Redemption of preferred stock																																	168,500,000
Elimination original issuance costs																								5,500,000
Excess of the fair value of the common stock issued recognition as additional paid in capital																								43,600,000
Excess of the fair value of the common stock issued recognition as preferred stock																								58,800,000
Number of common stock shares exchanged for one shares of Series A Preferred Stock																																36.8046
Number of preferred stock outstanding																																27,461		28,939	28,939
Preferred stock tendered amount																							27,500,000
Elimination of original issuance costs																							900,000
Excess of fair value recognized, as increase to APIC																							26,400,000
Excess of fair value recognized, as reduction to retained earnings																							11,600,000
Invest through a direct purchase													115,000,000
Funding of investment																																								40,200,000			74,800,000
Common stock, shares issued						90,709,350	90,688,879		610,072									8,699,848	2,069,848					6,030,000														2,069,848		4,000,000			3,000,000
Warrants and rights issued																																								3,000,000			11,100,000
Exercisable to purchase																																									11,753	18,431
Common stock equivalent to preferred stock, exercisable to purchase																																					1,843,100
Exercisable warrants converted shares of common stock											6,800,000
Net gain on fair value adjustments on warrants												3,600,000
Beneficial conversion, increase to additional paid in capital												22,200,000
Payments to acquire common stock									6,900,000															350
Common stock, authorized						200,000,000	200,000,000																															6,630,000
Retained earnings																									$ 58,000,000	$ 58,000,000