Defined Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 28, 2017	Oct. 29, 2016	Oct. 28, 2017	Oct. 29, 2016	Jan. 28, 2017
Components of net periodic defined benefit pension cost
Service cost	$ 492	$ 381	$ 1,452	$ 1,152
Interest cost	483	482	1,446	1,446
Expected return on plan assets	(48)	(46)	(143)	(139)
Net amortization of unrecognized prior service credit	(7)	(7)	(20)	(21)
Net amortization of actuarial losses	116	86	344	257
Net periodic defined benefit pension cost	1,036	896	3,079	2,695
SERP
Defined Benefit Plans
SERP benefit payments	400	400	1,300	1,300
Components of net periodic defined benefit pension cost
Service cost	0	0	0	0
Interest cost	461	460	1,382	1,380
Expected return on plan assets	0	0	0	0
Net amortization of unrecognized prior service credit	0	0	0	0
Net amortization of actuarial losses	38	39	114	116
Net periodic defined benefit pension cost	499	499	1,496	1,496
SERP | Other income/expense
Defined Benefit Plans
Gains (losses) as a result of changes in value of the insurance policy investments, included in other income and expense	1,600	(500)	5,500	4,600
Swiss Pension Plan | Switzerland
Defined Benefit Plans
Projected benefit obligation	18,900		18,900		$ 17,600
Plan assets at fair value	15,400		15,400		14,100
Components of net periodic defined benefit pension cost
Service cost	492	381	1,452	1,152
Interest cost	22	22	64	66
Expected return on plan assets	(48)	(46)	(143)	(139)
Net amortization of unrecognized prior service credit	(7)	(7)	(20)	(21)
Net amortization of actuarial losses	78	47	230	141
Net periodic defined benefit pension cost	537	$ 397	1,583	$ 1,199
Other assets | SERP
Defined Benefit Plans
Cash surrender values of the insurance policies held in a rabbi trust	62,800		62,800		58,600
Accrued expenses and other long-term liabilities | SERP
Defined Benefit Plans
Projected benefit obligation	53,600		53,600		53,500
Other long-term liabilities | Swiss Pension Plan | Switzerland
Defined Benefit Plans
Net liability	$ 3,500		$ 3,500		$ 3,500