Investments in Affiliates - Equity Method Investment Summarized Balance Sheet Information (Details) - Joint Venture Unconsolidated [Member] - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Investments In And Advances To Affiliates [Line Items]
Equity Method Investment, Summarized Financial Information, Current Assets		$ 141,930	$ 31,320
Equity Method Investment, Summarized Financial Information, Noncurrent Assets		170,172	129,039
Equity Method Investment, Summarized Financial Information, Assets		312,102	160,359
Equity Method Investment, Summarized Financial Information, Current Liabilities		55,816	30,131
Equity Method Investment, Summarized Financial Information, Long-term Liabilities	[1]	63,098	31,636
Equity Method Investment, Summarized Financial Information, Total Liabilities		118,914	61,767
Equity Method Investments Summarized Financial Information Net Assets		193,188	98,592
Other Affiliates [Member]
Investments In And Advances To Affiliates [Line Items]
Equity Method Investment, Summarized Financial Information, Assets		312,100
Equity Method Investments		$ 84,354	$ 38,469

[1] The balance primarily relates to debt associated with our real estate investments. The increase in the balance since December 31, 2017 is related to debt of our foreign affiliates associated with purchase of equipment and buildings. See Note 15 for further discussion.