Defined Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 29, 2017	Apr. 30, 2016	Jan. 28, 2017
Components of net periodic defined benefit pension cost
Service cost	$ 491	$ 379
Interest cost	483	482
Expected return on plan assets	(49)	(46)
Net amortization of unrecognized prior service credit	(7)	(7)
Net amortization of actuarial losses	117	86
Net periodic defined benefit pension cost	1,035	894
SERP
Defined Benefit Plans
SERP benefit payments	400	400
Components of net periodic defined benefit pension cost
Service cost	0	0
Interest cost	461	460
Expected return on plan assets	0	0
Net amortization of unrecognized prior service credit	0	0
Net amortization of actuarial losses	38	39
Net periodic defined benefit pension cost	499	499
Swiss Pension Plan | Switzerland
Defined Benefit Plans
Projected benefit obligation	18,100		$ 17,600
Plan assets at fair value	14,600		14,100
Components of net periodic defined benefit pension cost
Service cost	491	379
Interest cost	22	22
Expected return on plan assets	(49)	(46)
Net amortization of unrecognized prior service credit	(7)	(7)
Net amortization of actuarial losses	79	47
Net periodic defined benefit pension cost	536	395
Other income/expense | SERP
Defined Benefit Plans
Gains as a result of changes in value of the insurance policy investments, included in other income	1,900	$ 3,200
Other assets | SERP
Defined Benefit Plans
Cash surrender values of the insurance policies held in a rabbi trust	60,100		58,600
Accrued expenses and other long-term liabilities | SERP
Defined Benefit Plans
Projected benefit obligation	53,600		53,500
Other long-term liabilities | Swiss Pension Plan | Switzerland
Defined Benefit Plans
Net liability	$ 3,500		$ 3,500