Income Taxes Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Effective Tax Rate	(63.50%)	33.50%	(16.90%)	32.70%
PROVISION/ (BENEFIT) FOR INCOME TAXES	$ (60,413)	$ 29,668	$ (31,604)	$ 58,807
U.S Federal Statutory Income Tax Rate							35.00%
Income Taxes Paid			38,163	44,539
Unrecognized Tax Benefits	9,607		9,607				$ 9,607
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	8,679		8,679				8,679
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	1,318	$ 1,284	1,318	$ 1,284			1,318
Minimum [Member]
Expiration of statutes of limitations impact on UTB balance	500		500				500
Maximum [Member]
Expiration of statutes of limitations impact on UTB balance	1,500		1,500				1,500
Scenario, Forecast [Member]
U.S Federal Statutory Income Tax Rate					21.00%	28.00%
Tax Cuts and Jobs Act [Member]
PROVISION/ (BENEFIT) FOR INCOME TAXES	(96,766)
Other Recent Tax Pronouncements [Member]
Unrecognized Tax Benefits	$ 3,391		$ 3,391				$ 3,391