Income Taxes, Provision for income Taxes (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Currently (receivable) payable [Abstract]
Federal	[1]	$ 12,994	$ (9,071)	$ 15,513
State		2,622	205	642
Foreign		22,680	23,187	25,254
Current income tax (expense), total		38,296	14,321	41,409
Deferred expense (benefit) [Abstract]
Federal		(17,246)	3,977	18,458
State		18	3,164	215
Foreign		(2,112)	2,703	(1,259)
Deferred income tax (expense), total		(19,340)	9,844	17,414
Income taxes		18,956	24,165	$ 58,823
Transition tax for accumulated foreign earnings, Income tax (benefit) expense		$ (3,900)	7,400
Transition tax for accumulated foreign earnings, Liability, Noncurrent			$ 0

[1] In 2018 and 2017, this amount includes $(3.9) million and $7.4 million, respectively, of income tax (benefit) expense related to the one-time transition tax on earnings of foreign subsidiaries enacted by the 2017 Tax Legislation (See discussion below). There was no liability for this amount recorded as of December 31, 2018.