Parent Company Information (Components of Condensed Balance Sheets The Parent Company) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010
Assets:
Cash and due from banks	$ 223,616		$ 252,283		$ 195,957	$ 159,849
Interest-bearing deposits	23,674		98,205
Securities available for sale, at fair value	3,106,931		3,136,160
Other assets	260,687		259,742
Total assets	20,852,999		20,146,765		18,714,340
Liabilities and shareholders' equity:
Senior notes	150,000		150,000
Junior subordinated debt	77,320	[1]	77,320	[1]
Total liabilities	18,643,811		18,053,235
Shareholders’ equity	2,209,188		2,093,530
Total liabilities and shareholders' equity	20,852,999		20,146,765
Parent Company [Member]
Assets:
Cash and due from banks	12,452		10,091		15,403	9,625
Interest-bearing deposits	261,121		220,110
Securities available for sale, at fair value	3,584		16,734
Investment in subsidiaries	2,142,222		2,057,350
Due from (to) subsidiaries	37		(22)
Alternative investments	11,016		11,623
Other assets	11,859		11,971
Total assets	2,442,291		2,327,857
Liabilities and shareholders' equity:
Senior notes	151,045		154,170
Junior subordinated debt	77,320		77,320
Accrued interest payable	1,732		1,728
Other liabilities	3,006		1,109
Total liabilities	233,103		234,327
Shareholders’ equity	2,209,188		2,093,530
Total liabilities and shareholders' equity	$ 2,442,291		$ 2,327,857

[1] The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95%, was 3.194% at December 31, 2013 and 3.258% at December 31, 2012.