Debt (Narrative) (Details)				3 Months Ended		6 Months Ended
	Jun. 02, 2021 USD ($)	Jun. 01, 2021	Jun. 18, 2020 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) day	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 01, 2017 USD ($)
Line of Credit Facility [Line Items]
Secured term loan facility				$ 316,122,000		$ 316,122,000		$ 317,627,000
Debt issuance costs						0	$ 2,219,000
Long-term debt				308,531,000		308,531,000		309,123,000
Interest expense				4,100,000	$ 4,900,000	$ 8,000,000	8,900,000
Interest Expense
Line of Credit Facility [Line Items]
Debt issuance costs	$ 361,000
Debt extinguishment costs	$ 474,000
Credit Agreement
Line of Credit Facility [Line Items]
Revolving credit facility, percentage repaid for no covenants						25.00%
Convertible senior notes
Line of Credit Facility [Line Items]
Interest rate on amounts borrowed			4.25%
Face value			$ 100,000,000
Proceeds from issuance of convertible debt			$ 96,500,000
Conversion ratio			0.0426203
Conversion price (in dollars per share) | $ / shares			$ 23.46
Debt fair value				$ 107,000,000		$ 107,000,000
Effective interest rate				5.05%		5.05%
Interest expense				$ 1,200,000	$ 1,200,000	$ 2,500,000	$ 2,400,000
Unamortized debt issuance costs				2,200,000		$ 2,200,000
Convertible senior notes | Circumstance I
Line of Credit Facility [Line Items]
Conversion trading day threshold | day						20
Conversion consecutive trading day threshold | day						30
Conversion percentage of stock price threshold						130.00%
Convertible senior notes | Circumstance II
Line of Credit Facility [Line Items]
Conversion trading day threshold | day						5
Conversion consecutive trading day threshold | day						5
Conversion percentage of stock price threshold						98.00%
Convertible senior notes | Circumstance After July 5, 2023
Line of Credit Facility [Line Items]
Conversion trading day threshold | day						20
Conversion consecutive trading day threshold | day						30
Conversion percentage of stock price threshold						130.00%
Conversion percentage of principal amount						100.00%
2.45% Sparkasse Zollernalb (KFW Loan 1)
Line of Credit Facility [Line Items]
Secured term loan facility				$ 403,000		$ 403,000		566,000
Interest rate on amounts borrowed				2.45%		2.45%
1.40% Sparkasse Zollernalb (KFW Loan 2)
Line of Credit Facility [Line Items]
Secured term loan facility				$ 844,000		$ 844,000		1,061,000
Interest rate on amounts borrowed				1.40%		1.40%
Secured Debt
Line of Credit Facility [Line Items]
Credit facility aggregate commitments									$ 255,000,000
Term loan balance
Line of Credit Facility [Line Items]
Secured term loan facility				$ 214,875,000		$ 214,875,000		$ 216,000,000	225,000,000
Term loan balance | Credit Agreement | Circumstance I
Line of Credit Facility [Line Items]
Debt instrument, extension circumstance period	91 days
Term loan balance | Credit Agreement | Circumstance II
Line of Credit Facility [Line Items]
Debt instrument, extension circumstance period	182 days
Term loan balance | Base Rate
Line of Credit Facility [Line Items]
Credit facility margin		2.25%
Term loan balance | Base Rate | Credit Agreement
Line of Credit Facility [Line Items]
Credit facility margin	2.50%
Term loan balance | LIBOR
Line of Credit Facility [Line Items]
Credit facility margin		3.25%
Term loan balance | LIBOR | Credit Agreement
Line of Credit Facility [Line Items]
Credit facility margin	3.50%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit facility aggregate commitments									$ 30,000,000
Revolving Credit Facility And Term Loan
Line of Credit Facility [Line Items]
Debt issuance costs	$ 2,100,000
Amortization of the debt issuance costs	$ 1,800,000
Revolving Credit Facility And Term Loan | Credit Agreement
Line of Credit Facility [Line Items]
Debt instrument, extension period	2 years 6 months
Revolving Credit Facility And Term Loan | Convertible senior notes | Credit Agreement
Line of Credit Facility [Line Items]
Interest rate on amounts borrowed	4.25%
Accounting Standards Update 2020-06 | Cumulative Effect, Period of Adoption, Adjustment | Convertible senior notes
Line of Credit Facility [Line Items]
Long-term debt				$ 100,000,000		$ 100,000,000