Income Taxes, Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation [Abstract]
U.S. federal corporate statutory rate		35.00%	35.00%	35.00%
State and local taxes, less federal tax benefit		3.10%	4.00%	2.30%
U.S. deferred tax rate change from 35% to 21%		79.50%	0.00%	0.00%
Net effects of foreign tax rate differential		6.20%	19.90%	1.50%
Sale of subsidiary		(4.60%)	(17.10%)	0.00%
Repatriation cost		3.80%	4.40%	(0.30%)
U.S. transition tax toll charge net of FTC		(56.20%)	0.00%	0.00%
ASC 740-30		61.20%	26.30%	(2.00%)
Valuation allowance changes		(1.10%)	(15.90%)	(0.50%)
Impairment of goodwill and intangible assets		0.00%	(0.60%)	(31.70%)
Uncertain tax positions		1.90%	(7.00%)	(0.40%)
Nondeductible equity compensation		(9.20%)	0.00%	0.00%
Nondeductible foreign interest expense		(3.00%)	0.00%	0.00%
Other, net		(0.30%)	1.50%	0.10%
Effective income tax rate		116.30%	50.50%	4.00%
Plan [Member]
Effective Income Tax Rate Reconciliation [Abstract]
U.S. federal corporate statutory rate	21.00%