CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2018
Payments for Repurchase of Common Stock	$ 15,000,000.0	$ 0
Impaired Assets to be Disposed of by Method Other than Sale, Amount of Impairment Loss	1,300,000	0
Cash and Cash Equivalents, Period Increase (Decrease)	69,400,000	(32,200,000)
Increase (Decrease) in Other Operating Assets and Liabilities, Net	1,700,000	4,300,000
Increase (Decrease) in Other Current Assets	4,100,000	(1,800,000)
Net Cash Provided by (Used in) Investing Activities, Total	(7,800,000)	(26,500,000)
Net Cash Provided by (Used in) Financing Activities, Total	78,900,000	5,300,000
Adjustments to reconcile net loss to cash from operating activities:
Depreciation and amortization	15,300,000	13,300,000
Stock-based compensation	3,500,000	6,700,000
Non-cash interest expense and amortization of debt issuance costs	2,100,000	2,000,000.0
Loss on disposal of fixed assets	100,000	0
Deferred income taxes	(500,000)	(500,000)
Other, net	(1,700,000)	(4,300,000)
Proceeds from the sale of business			$ 135,100,000
Gain (Loss) on Disposition of Property Plant Equipment	(100,000)	0
Changes in assets and liabilities (excluding effects of foreign exchange):
Receivables, net	38,800,000	11,200,000
Inventories, net	(22,100,000)	(16,300,000)
Prepaid and other current assets	(5,600,000)	(2,900,000)
Accounts payable	(6,300,000)	(3,500,000)
Accrued compensation and employee benefits	(10,300,000)	(17,400,000)
Other accrued expenses	0	1,800,000
Accrued taxes	2,900,000	400,000
Net Cash Provided by (Used in) Operating Activities	(1,500,000)	(11,200,000)
Investing Activities
Additions to property, plant, and equipment	(7,800,000)	(15,100,000)
Acquisitions of business (net of cash acquired)	0	(11,400,000)
Proceeds from the sale of business			135,100,000
Financing Activities
Borrowings under revolving credit facility	100,000,000.0	10,000,000.0
Tax on restricted and performance stock unit vesting	(5,800,000)	(4,800,000)
Payments of finance lease obligations	(500,000)	(400,000)
Payment of consideration owed for acquisitions	0	(200,000)
Net proceeds from exercise of stock-based awards	200,000	700,000
Effect of Exchange Rate on Cash and Cash Equivalents [Abstract]
Effect of exchange rate changes on cash and cash equivalents	(200,000)	200,000
Net loss	(9,100,000)	(2,700,000)
Net increase (decrease) in cash and cash equivalents	69,400,000	(32,200,000)
Cash and Cash Equivalents, at Carrying Value, Including Discontinued Operations	78,400,000	73,500,000
Cash and Cash Equivalents, at Carrying Value, Including Discontinued Operations	147,800,000	41,300,000	$ 73,500,000
Supplemental information - cash paid for:
Income taxes	5,400,000	4,400,000
Interest	400,000	500,000
Payments for Repurchase of Common Stock	$ 15,000,000.0	$ 0