Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Name:	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Cash, cash equivalents, and restricted cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 361,348	$ 568,532
Restricted cash	53,879	29,173
Cash, cash equivalents, and restricted cash	415,227	597,705	$ 242,689	$ 272,130
Funds held in trust under the terms of certain secured notes payable
Cash and Cash Equivalents [Line Items]
Restricted cash	17,264	17,256
Funds held in escrow related to construction projects and investing activities
Cash and Cash Equivalents [Line Items]
Restricted cash	30,000	4,580
Other restricted cash
Cash and Cash Equivalents [Line Items]
Restricted cash	$ 6,615	$ 7,337