Derivatives Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2019	Jun. 30, 2017	Mar. 31, 2016
Derivative [Line Items]
Convertible Debt 2022 Conversion Feature, Initial Fair Value	$ 28,859,000
Proceeds from Issuance of Warrants				$ 12,376,000
Foreign currency forward contracts
Derivative [Line Items]
Notional amount of derivatives, matured during period	42,894,000	$ 32,152,000
Selling, General and Administrative Expenses | Foreign currency forward contracts
Derivative [Line Items]
Loss on derivative	$ (724,000)	(12,000)
Minimum
Derivative [Line Items]
Derivative, percentage of forcasted transactions with currency rate exposure	50.00%
Maximum
Derivative [Line Items]
Derivative, percentage of forcasted transactions with currency rate exposure	90.00%
Cash Flow Hedging [Member]
Derivative [Line Items]
Gain (Loss)	$ (150,000)	240,000
Cash Flow Hedging [Member] | Sales [Member]
Derivative [Line Items]
Gain recognized in income		156,000
Loss on derivative	(115,000)
Cash Flow Hedging [Member] | Cost of Sales [Member]
Derivative [Line Items]
Gain recognized in income		$ 84,000
Loss on derivative	(35,000)
Convertible Subordinated Debt | Convertible Senior Notes at 5.00% February 2021 [Member]
Derivative [Line Items]
Convertible due 2021 - Bond Hedge, Initial Fair Value	27,975,000
Convertible Debt Conversion Feature, Initial Fair Value	(34,480,000)
Debt Instrument, Face Amount	$ 61,091,000				$ 61,091,000		$ 150,000,000
Interest rate (as a percent)	5.00%
Convertible Subordinated Debt | Convertible Senior Notes at 4.50% February 2022 [Domain]
Derivative [Line Items]
Proceeds from Issuance of Warrants			$ 14,100,000
Convertible due 2022 - Bond Hedge, Fair Value at Issuance	$ 24,780,000
Debt Instrument, Face Amount	$ 120,000,000				$ 120,000,000	$ 120,000,000
Interest rate (as a percent)	4.50%