Income Taxes - Schedule of Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Stock based compensation	$ 1,757	$ 1,337
Net operating loss and tax credit carryforwards	86,879	38,622
Interest expense limitation	7,620
Pension obligation	13,473	3,302
Excess and obsolete inventory	3,217	2,161
Deferred revenue	3,305	6,903
Employee bonuses and commissions	2,537	1,874
Depreciation and Amortization	29,015	29,525
Operating lease liabilities	23,451
Other	9,685	9,961
Deferred tax assets	180,939	93,685
Less: Valuation allowance	(76,206)	(30,924)
Net deferred tax assets	104,733	62,761
Depreciation and amortization	41,549	17,723
Unremitted earnings	4,740	3,529
Operating lease right-of-use assets	22,774
Other	2,966	1,267
Deferred tax liabilities	72,029	22,519
Net deferred tax assets	32,704	40,242
Deferred income tax assets	42,656	47,099
Deferred income tax liabilities	$ 9,952	$ 6,988