Retirement Benefit Plans (Narrative) (Detail) - USD ($) $ in Thousands		12 Months Ended			35 Months Ended
	Feb. 01, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 01, 2012	Jul. 01, 2015
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation		$ 218,000	$ 224,700
Net actuarial loss		7,200
Prior service cost		$ 14
Assumed healthcare cost trend (as a percent)		8.00%
Healthcare-cost trend rate in 2018 (as a percent)		5.00%
Employer matching contribution, percent of match	100.00%				100.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent					5.00%
Election period (in days)					90 years
Employer matching contribution, percent of employees' gross pay	2.00%				3.00%
Defined Benefit Plan, Non-Elective Contributions To Plan Participants, Percentage		2.00%
Employer matching contribution, additional percent of match	50.00%
Employer additional matching contribution, percent of employees' gross pay	6.00%
Compensation expense		$ 10,900	10,600	$ 11,200
Multiemployer Plans, Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan						$ (900)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		$ 0	$ 0
Expected long-term return on assets (as a percent)		7.00%	7.25%	7.50%
Funded status of plan		$ (42,276)	$ (37,572)
Webster SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		241	143
Funded status of plan		(10,518)	(10,041)
Postretirement Health Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		$ 225	$ 297
Assumed healthcare cost trend (as a percent)		8.00%	8.00%	8.00%
Increase in net periodic postretirement benefit cost if trend increased by 1%		$ 6
Increase in accumulated benefit obligation if trend increased by 1%		211
Decrease in net periodic postretirement benefit cost if trend rate decreased by 1%		6
Decrease in accumulated benefit obligation if trend rate decreased 1%		190
Funded status of plan		$ (3,853)	$ (4,133)