Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																12 Months Ended
	Nov. 30, 2018		Aug. 31, 2018		May 31, 2018		Feb. 28, 2018		Nov. 30, 2017		Aug. 31, 2017		May 31, 2017		Feb. 28, 2017		Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2016
Condensed Income Statements, Captions [Line Items]
Net Sales	$ 191.3		$ 193.6		$ 206.3		$ 178.7		$ 186.3		$ 200.9		$ 221.3		$ 174.6		$ 769.8	$ 783.1	$ 759.9
Gross profit(1)(2)	43.5	[1],[2]	49.1	[1],[2]	51.6	[1],[2]	46.6	[1],[2]	45.9	[1],[2]	57.8	[1],[2]	53.2	[1],[2]	43.9	[1],[2]	190.7	200.8	203.9
Restructuring and severance	1.7		0.3		0.2		1.3		0.6		0.4		3.6		1.0		3.5	5.7	11.1
(Gain) Loss on asset sales	0.9		0.0		0.0		0.0		0.4		0.0		0.0		0.0		(0.9)	0.4	0.3
Asset impairments and write-offs	3.9		9.2		0.4		0.0		19.6		0.4		12.9		0.0		13.5	32.9	5.7
Debt issuance costs write-off	0.0		0.0		0.0		0.8										0.8	0.0	2.9
Net income (loss)	$ 6.9	[3]	$ (1.9)	[3]	$ 8.4	[3]	$ 7.3	[3]	$ (92.9)	[3]	$ 7.9	[3]	$ (6.3)	[3]	$ 3.6	[3]	$ 20.7	$ (87.8)	$ (0.4)
Net income (loss) per share(4)
Net income (loss) per basic and diluted share(4)	$ 0.15	[4]	$ (0.04)	[4]	$ 0.19	[4]	$ 0.16	[4]	$ (2.10)	[4]	$ 0.18	[4]	$ (0.14)	[4]	$ 0.08	[4]	$ 0.46	$ (1.98)	$ (0.01)
Maximum [Member]
Net income (loss) per share(4)
Common stock price range per share	10.70		10.80		11.90		11.60		11.45		10.15		9.90		10.05		10.70	11.45
Minimum [Member]
Net income (loss) per share(4)
Common stock price range per share	$ 7.36		$ 8.30		$ 9.95		$ 9.55		$ 8.70		$ 8.40		$ 8.55		$ 8.60		$ 7.36	$ 8.70

[1] Gross profit excludes depreciation and amortization expense. Depreciation and amortization expense related to manufacturing facilities and equipment was $4.9 million, $5.0 million, $5.5 million, and $5.4 million for the three months ended February 28, 2018, May 31, 2018, August 31, 2018, and November 30, 2018 and $4.7 million, $4.8 million, $4.8 million, and $5.0 million for the three months ended February 28, 2017, May 31, 2017, August 31, 2017, and November 30, 2017, respectively.

[2] Gross profit includes net LIFO inventory reserve adjustments of $0.8 million of expense, $1.5 million of expense, $0.9 million of expense, and $0.6 million of expense for the three months ended February 28, 2018, May 31, 2018, August 31, 2018 and November 30, 2018, respectively, and $1.3 million of expense, $0.3 million of expense, $1.2 million of income and $1.0 million of expense for the three months ended February 28, 2017, May 31, 2017, August 31, 2017, and November 30, 2017, respectively.

[3] The Company’s income tax benefit (expense) was $6.2 million and $(83.7) million for 2018 and 2017, respectively. The 2017 income tax expense was significantly higher than 2018 primarily as a result of a $79.9 million income tax expense related to valuation allowances on deferred tax assets recorded in 2017. Of that amount, $75.7 million income tax expense was recorded in the U.S. during the fourth quarter of 2017.

[4] The sum of the quarterly earnings per share amounts may not equal the annual amount due to changes in the number of shares outstanding during the year.