Restructuring (Details) $ in Thousands	12 Months Ended
	Mar. 31, 2017 USD ($) store	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2020 store
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 29,087	$ 24,856	$ 0
Brand Realignment
Restructuring Cost and Reserve [Line Items]
Restructuring costs	29,100	24,800
Restructuring reserve	11,100	12,900
Brand Realignment | Selling, General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring costs	29,100	22,800
Brand Realignment | Cost of Sales
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0	2,000
Brand Realignment | Facility Closing
Restructuring Cost and Reserve [Line Items]
Number of stores closed | store	25
Number of stores identified for potential closure | store	12
Brand Realignment | Facility Closing | Selling, General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 3,600
Brand Realignment | Leasehold impairments
Restructuring Cost and Reserve [Line Items]
Restructuring costs	3,600	5,800
Restructuring reserve	$ 0	$ 0
Scenario, Forecast
Restructuring Cost and Reserve [Line Items]
Number of stores identified for potential closure | store				125