Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2016
Income Tax Examination [Line Items]
Reduction in deferred tax liability, recorded as income tax benefit	$ 619,000
Provisional reasonable estimate related to transition tax	33,000
Deferred Tax Assets Direct Financing Leases And Other Assets	7,000		$ 9,000
Undistributed foreign earnings	774,000
Undistributed earnings impacted by transition tax	345,000
Net operating loss carryforwards	171,053		396,313
Alternative minimum taxes	22,552		13,901
Unrecognized tax benefits that would affect the effective tax rate in future periods	56,000
Deferred income tax accrued interest and penalties	5,000
Income tax related to interest and penalties		$ 1,000
Decrease in unrecognized tax benefits related to federal, state and foreign tax positions	3,000
Total assets of variable interest entities	232,000
Total liabilities of variable interest entities	140,000		$ 140,000
Domestic Country
Income Tax Examination [Line Items]
Net operating loss carryforwards	128,000
Other Jurisdictions
Income Tax Examination [Line Items]
Net operating loss carryforwards	29,000
Foreign Country
Income Tax Examination [Line Items]
Net operating loss carryforwards	$ 14,000