Income Taxes, Tax Reconciliation and Tax Cuts and Jobs Act (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2019	Dec. 31, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective tax rate reconciliation [Abstract]
Taxes at statutory rate				21.00%	21.00%	21.00%
State income taxes, net of federal income tax benefit				2.20%	2.20%	1.10%
Tax credits				(1.50%)	(2.60%)	(1.50%)
Taxes on foreign earnings				2.80%	5.10%	(0.40%)
Global Intangible Low-Taxed Income				0.10%	0.90%	0.60%
Foreign Derived Tangible Income				(1.10%)	(1.00%)	(0.60%)
Loss on balance sheet hedge				2.00%	0.00%	0.00%
Resolution of prior years' tax matters				(0.10%)	(0.40%)	(0.30%)
Valuation allowance adjustments				(3.70%)	(8.80%)	0.40%
2017 Tax Legislation				0	0	(0.037)
U.S. tax accounting method changes				0.00%	0.00%	(2.90%)
Other, net				(1.10%)	2.40%	(0.40%)
Effective tax rate				20.60%	18.80%	13.30%
Valuation Allowance [Abstract]
Valuation allowance	[1]			$ (47,813)	$ (54,326)
Increase in valuation allowance amount		$ 16,200
Increase in valuation allowance for deferred tax assets, related to operating losses					$ 6,800
2017 Tax Act [Abstract]
Income tax expense			$ 18,400			$ 11,800
Provisional income tax expense, change in amount						$ (6,600)

[1] In the first quarter of 2019, the Company recognized an increase in its foreign tax credit carryover and corresponding valuation allowance of $16.2 million, related to the finalization of certain tax regulations.