Debt (Debt Repayment) (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2016	$ 18,091
2017	14,612
2018	12,227
2019	497,531
2020	290,194
2021	310,012
Thereafter	996,724
Total Debt	2,139,391
Interest imputed on Capital Leases	(2,986)
Original issuer's discount	(548)
Current portion	(17,141)
Non-current portion	2,118,716
Capital Leases
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2016	1,935
2017	1,934
2018	1,936
2019	1,934
2020	1,934
2021	1,936
Thereafter	1,233
Total Debt	12,842
Interest imputed on Capital Leases	(2,986)
Original issuer's discount	0
Current portion	(1,163)
Non-current portion	8,693
Line of Credit
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2016	314
2017	312
2018	321
2019	317
2020	95
2021	300,011
Thereafter	800,000
Total Debt	1,101,370
Interest imputed on Capital Leases	0
Original issuer's discount	0
Current portion	(314)
Non-current portion	1,101,056
Non- Recourse
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2016	12,842
2017	9,366
2018	6,970
2019	7,280
2020	7,665
2021	8,065
Thereafter	195,491
Total Debt	247,679
Interest imputed on Capital Leases	0
Original issuer's discount	(548)
Current portion	(12,664)
Non-current portion	234,467
Revolver
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2016	0
2017	0
2018	0
2019	485,000
2020	0
2021	0
Thereafter	0
Total Debt	485,000
Interest imputed on Capital Leases	0
Original issuer's discount	0
Current portion	0
Non-current portion	485,000
Term Loan
Debt repayment schedules under capital lease obligations, long-term debt and non-recourse debt
2016	3,000
2017	3,000
2018	3,000
2019	3,000
2020	280,500
2021	0
Thereafter	0
Total Debt	292,500
Interest imputed on Capital Leases	0
Original issuer's discount	0
Current portion	(3,000)
Non-current portion	$ 289,500