Changes in Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	$ 1,610,430	$ 1,464,141	$ 1,542,945	$ 1,430,525
Net income	26,241	49,323	92,957	106,320
Other comprehensive income (loss)	(1,081)	1,301	(290)	1,638
Share-based compensation	2,030	2,471	6,787	10,163
Convertible note repayment allocated to conversion option		(929)		(929)
Issuance of common stock, net	(2)	(703)	(1,531)	(1,203)
Contributions from noncontrolling interests	3,000		7,000
Distributions to noncontrolling interests	(10,000)	(6,307)	(17,250)	(37,217)
Balance at the end of the period	1,630,618	1,509,297	1,630,618	1,509,297
Common Stock
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	51,072	50,771	50,827	50,279
Issuance of common stock, net		56	245	548
Balance at the end of the period	51,072	50,827	51,072	50,827
Additional Paid-in Capital
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	1,130,368	1,124,672	1,127,385	1,117,972
Share-based compensation	2,030	2,471	6,787	10,163
Convertible note repayment allocated to conversion option		(929)		(929)
Issuance of common stock, net	(2)	(759)	(1,776)	(1,751)
Balance at the end of the period	1,132,396	1,125,455	1,132,396	1,125,455
Retained Earnings
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	469,584	350,071	422,385	313,991
Net income	15,394	36,819	62,593	72,899
Balance at the end of the period	484,978	386,890	484,978	386,890
Accumulated Other Comprehensive Loss
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	(46,526)	(40,597)	(46,741)	(42,100)
Other comprehensive income (loss)	(634)	781	(419)	2,284
Balance at the end of the period	(47,160)	(39,816)	(47,160)	(39,816)
Noncontrolling Interests
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	5,932	(20,776)	(10,911)	(9,617)
Net income	10,847	12,504	30,364	33,421
Other comprehensive income (loss)	(447)	520	129	(646)
Contributions from noncontrolling interests	3,000		7,000
Distributions to noncontrolling interests	(10,000)	(6,307)	(17,250)	(37,217)
Balance at the end of the period	$ 9,332	$ (14,059)	$ 9,332	$ (14,059)