Investments in Non-Consolidated Affiliates (Unaudited) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Noncontrolling Interest [Line Items]
Assets, Current	$ 259,221				$ 184,503				$ 259,221	$ 184,503
NET EARNINGS									69,285	18,495	$ 23,488
Liabilities, Current	229,134				184,672				229,134	184,672
Liabilities	2,034,147				1,153,565				2,034,147	1,153,565
REVENUES	280,779	$ 204,919	$ 203,607	$ 203,040	322,971	$ 254,101	$ 253,211	$ 237,917	892,345	1,068,200	768,870
Noncontrolling Interest [Member]
Noncontrolling Interest [Line Items]
Assets, Current	64,262				50,516				64,262	50,516
Total Expenses									(228,169)	(196,334)	(170,317)
NET EARNINGS									(26,141)	(23,808)	(12,372)
Long-Lived Assets	80,724				103,174				80,724	103,174
Liabilities, Current	(38,938)				(33,315)				(38,938)	(33,315)
Liabilities	(102,657)				(117,338)				(102,657)	(117,338)
Stockholders' Equity Attributable to Noncontrolling Interest	$ (3,391)				$ (3,037)				(3,391)	(3,037)
REVENUES									$ 202,028	$ 172,526	$ 157,945