Income Taxes Effective Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax provision at statutory rate, Percent		35.00%	35.00%	35.00%
Effect of foreign operations, Percent		(1.10%)	4.30%	(3.80%)
Foreign valuation allowance, Percent		(0.30%)	2.90%	2.10%
Foreign goodwill impairment, Percent		0.00%	2.40%	0.00%
Effect of foreign tax rate change, Percent		0.00%	(2.00%)	(3.30%)
Effect of U.S. transition (toll) tax, Percent		7.20%	0.00%	0.00%
Effect of U.S. federal rate change, Percent		(133.30%)	0.00%	0.00%
State income taxes, net of federal income tax benefit, Percent		3.80%	4.10%	3.00%
Benefit of track maintenance credit, Percent		(0.00%)	(13.40%)	(9.10%)
Other, net, Percent		0.30%	1.20%	1.30%
Effective Income Tax Rate, Percent		(88.40%)	34.50%	25.20%
Change in Effective Tax Rate, Percent			9.30%
Scenario, Forecast [Member]
Tax provision at statutory rate, Percent	21.00%