Share-Based Compensation Plans - Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Aug. 03, 2019	Aug. 04, 2018	Aug. 03, 2019	Aug. 04, 2018
Share-based compensation
Share-based compensation expense	$ 2.4	$ 5.5	$ 4.3	$ 11.9
Stock Options
Number of Shares
Outstanding at the beginning of the period (in shares)			1,252,072
Granted (in shares)			3,050,974
Forfeited (in shares)			(171,812)
Expired (in shares)			(43,268)
Outstanding at the end of the period (in shares)	4,087,966		4,087,966
Exercisable at the end of the period (in shares)	912,456		912,456
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)			$ 23.64
Granted (in dollars per share)			7.61
Forfeited (in dollars per share)			11.02
Expired (in dollars per share)			28.28
Outstanding at the end of the period (in dollars per share)	$ 12.16		12.16
Exercisable at the end of the period (in dollars per share)	$ 24.91		24.91
Additional disclosures
Weighted-average grant date fair value of stock options granted (in dollars per share)			$ 3.00
Unrecognized compensation cost
Compensation recognition period, non-vested awards			1 year 8 months 12 days
Stock Appreciation Rights ("SARs")
Number of Shares
Granted (in shares)			414,476
Outstanding at the end of the period (in shares)	414,476		414,476
Weighted-Average Exercise Price
Granted (in dollars per share)			$ 7.62
Outstanding at the end of the period (in dollars per share)	$ 7.62		7.62
Additional disclosures
Weighted-average grant date fair value of stock options granted (in dollars per share)			$ 3.01
Assumptions used to value stock options
Risk-free interest rate (as a percent)			2.39%
Expected lives (in years)			5 years
Dividend yield (as a percent)			4.34%
Expected volatility (as a percent)			62.32%
Stock Options And Stock Appreciation Rights ("SARs")
Unrecognized compensation cost
Unrecognized compensation cost, non-vested awards	$ 10.6		$ 10.6