Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Accrued employee benefits and compensation	$ 10,647	$ 6,199
Net operating loss carryforwards	3,785	2,563
Tax credit carryforwards	13,170	15,081
Reserves and accruals	5,145	6,581
Operating leases	4,191	665
Capitalized research and development	16,622	14,167
Other	5,299	1,824
Total deferred tax assets	58,859	47,080
Less deferred tax asset valuation allowance	(9,775)	(9,250)	$ (14,625)	$ (16,889)
Total deferred tax assets, net of valuation allowance	49,084	37,830
Deferred tax liabilities
Depreciation and amortization	32,669	10,282
Postretirement benefit obligations	2,071	2,001
Unremitted earnings	2,335	2,426
Operating leases	4,422	714
Other	4,367	2,115
Total deferred tax liabilities	45,864	17,538
Net deferred tax asset (liability)	$ 3,220	$ 20,292