Investments in Affiliates - Equity Method Investment Summarized Balance Sheet Information (Details) - Joint Venture Unconsolidated [Member] - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Investments In And Advances To Affiliates [Line Items]
Equity Method Investment, Summarized Financial Information, Current Assets		$ 138,564	$ 141,930	$ 136,953
Equity Method Investment, Summarized Financial Information, Noncurrent Assets		182,561	170,172	173,384
Equity Method Investment, Summarized Financial Information, Assets		321,125	312,102	310,337
Equity Method Investment, Summarized Financial Information, Current Liabilities		70,435	55,816	54,710
Equity Method Investment, Summarized Financial Information, Long-term Liabilities	[1]	70,381	63,098	54,383
Equity Method Investment, Summarized Financial Information, Total Liabilities		140,816	118,914	109,093
Equity Method Investments Summarized Financial Information Net Assets		180,309	193,188	201,244
Other Affiliates [Member]
Investments In And Advances To Affiliates [Line Items]
Equity Method Investment, Summarized Financial Information, Assets		321,100
Equity Method Investments		$ 82,109	$ 84,354	$ 99,495

[1] The balance primarily relates to debt associated with our real estate investments.