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Fair Value Measurements and Financial Instruments - Schedule of Estimated Fair Value of Partnership's Financial Instruments on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value / Carrying Amount of Asset (Liability) $	$ (202)
Cash and restricted cash – current	253,291	$ 222,864	$ 339,435	$ 243,173
Long-term debt	(1,831,396)	(1,969,776)
Finance lease, liability	1,410,904
Capital Lease Obligations		1,298,556
Carrying Amount Asset (Liability)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Advances to equity-accounted joint ventures	126,546	131,386
Carrying Amount Asset (Liability) \| Level 1 \| Public
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	(345,824)	(350,813)
Carrying Amount Asset (Liability) \| Level 1 \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and restricted cash – current	253,291
Cash, Cash Equivalents, and Short-term Investments		222,864
Carrying Amount Asset (Liability) \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Finance lease, liability	1,410,904
Capital Lease Obligations		1,298,556
Carrying Amount Asset (Liability) \| Level 2 \| Non-public
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	(1,485,572)	(1,618,963)
Carrying Amount Asset (Liability) \| Level 2 \| Recurring \| Interest rate swap agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements – assets	2,210	3,341
Interest rate swap agreements – liabilities	(50,447)	(40,958)
Carrying Amount Asset (Liability) \| Level 2 \| Recurring \| Cross-currency swap agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value / Carrying Amount of Asset (Liability) $	(202)	0
Cross currency swap agreements – liabilities	(42,104)	(29,122)
Carrying Amount Asset (Liability) \| Level 3 \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other derivative	0	1,061
Fair Value Asset (Liability) \| Level 1 \| Public
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	(358,005)	(361,095)
Fair Value Asset (Liability) \| Level 1 \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and restricted cash – current	253,291
Cash, Cash Equivalents, and Short-term Investments		222,864
Fair Value Asset (Liability) \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Finance lease, liability	1,434,910
Capital Lease Obligations		1,274,693
Fair Value Asset (Liability) \| Level 2 \| Non-public
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	(1,474,208)	(1,604,106)
Fair Value Asset (Liability) \| Level 2 \| Recurring \| Interest rate swap agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements – assets	2,210	3,341
Interest rate swap agreements – liabilities	(50,447)	(40,958)
Fair Value Asset (Liability) \| Level 2 \| Recurring \| Cross-currency swap agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value / Carrying Amount of Asset (Liability) $	(202)	0
Cross currency swap agreements – liabilities	(42,104)	(29,122)
Fair Value Asset (Liability) \| Level 3 \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other derivative	$ 0	$ 1,061