Borrowings (Long-Term Debt) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Notes and subordinated debt		$ 227,320	$ 227,320
Long-term debt		$ 226,356	$ 226,237
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		3.48%	3.19%
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest rate spread of LIBOR plus (as a percent)		2.95%
Long-term Debt [Member]
Debt Instrument [Line Items]
Unamortized discount on senior fixed-rate notes		$ (964)	$ (1,083)
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.375%
Notes and subordinated debt		$ 150,000	150,000
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	[1]	$ 77,320	$ 77,320

[1] The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95%, was 3.48% at December 31, 2015 and 3.19% at December 31, 2014.