Debt (Debt Repayment) (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2018	$ 29,484
2019	23,622
2020	24,911
2021	296,492
2022	268,356
Thereafter	1,977,404
Long-term debt	2,620,269
Interest imputed on Capital Leases	(1,542)
Original issuer's discount	(3,770)
Current portion	(28,920)
Non-current portion	2,586,037
Capital Leases
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2018	1,936
2019	1,934
2020	1,934
2021	1,936
2022	1,233
Thereafter	0
Long-term debt	8,973
Interest imputed on Capital Leases	(1,542)
Original issuer's discount	0
Current portion	(1,372)
Non-current portion	6,059
Line of Credit
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2018	498
2019	499
2020	233
2021	142
2022	250,133
Thereafter	901,224
Long-term debt	1,152,729
Interest imputed on Capital Leases	0
Original issuer's discount	0
Current portion	(498)
Non-current portion	1,152,231
Non- Recourse
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2018	19,050
2019	13,189
2020	14,744
2021	15,855
2022	8,990
Thereafter	322,180
Long-term debt	394,008
Interest imputed on Capital Leases	0
Original issuer's discount	(271)
Current portion	(19,050)
Non-current portion	374,687
Revolver
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2018	0
2019	0
2020	0
2021	270,559
2022	0
Thereafter	0
Long-term debt	270,559
Interest imputed on Capital Leases	0
Original issuer's discount	0
Current portion	0
Non-current portion	270,559
Term Loan
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2018	8,000
2019	8,000
2020	8,000
2021	8,000
2022	8,000
Thereafter	754,000
Long-term debt	794,000
Interest imputed on Capital Leases	0
Original issuer's discount	(3,499)
Current portion	(8,000)
Non-current portion	$ 782,501

Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt.

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Imputed Interest on capital lease.

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Long-Term Debt, Maturities, Repayments Of Principal After Year Six

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Long term debt ,Nonrecourse Debt and capital lease obligation excluding current portion.

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Original issuer's discount.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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