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.

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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 (Reconciliation of Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Cash, Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	$ 207,130	$ 116,075
Restricted cash	6,261	3,788
Total cash, cash equivalents and restricted cash	213,391	119,863	$ 121,694	$ 197,648
Tutor Perini Corporation [Member]
Cash, Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	49,166	51,749
Joint Venture [Member]
Cash, Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	$ 157,964	$ 64,326