Income Taxes Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Derivative Instruments	$ 1,529	$ 5,514
Deferred income tax assets:
Net operating loss carryforwards	197,089	273,055
Passive activity loss carryforwards	7	12
Allowance for losses	622	4,250
Deferred income	261	35
Accrued liabilities and other payables	631	2,233
Total gross deferred tax assets	200,139	285,099
Less: Valuation allowance	0	(286)
Net deferred tax assets	200,139	284,813
Deferred income tax liabilities:
Accelerated depreciation	382,961	516,472
Derivative instruments	790	287
Deferred income	27,347	71,359
Deferred partnership income (TCI)	1,134	1,765
Other	1,205	9,607
Total gross deferred tax liability	415,578	602,129
Deferred Tax Assets, Net	215,439	317,316
Deferred Tax Liabilities, Goodwill and Intangible Assets	$ 2,141	$ 2,639