Stockholders' Equity (Details) $ / shares in Units, $ in Thousands		1 Months Ended							8 Months Ended	12 Months Ended
	May 03, 2013 shares	Dec. 31, 2016 USD ($) $ / shares shares	Aug. 31, 2016 USD ($) shares	Feb. 29, 2016 shares	Aug. 31, 2015 shares	Mar. 31, 2015 shares	Aug. 31, 2014 shares	Feb. 28, 2014 USD ($) shares	Sep. 30, 2014 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) item $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares
Common Stock
Common stock, shares authorized		90,000,000								90,000,000	90,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.0001								$ 0.0001	$ 0.0001
Common stock, shares issued		51,576,442								51,576,442	51,676,140
Common stock, shares outstanding		51,576,442								51,576,442	51,676,140
Number of holders of common stock | item										394
Shares of common stock issued as a part of quarterly compensation of non-employee members of the Board of Directors			11,745	10,450	9,748	8,168	6,172	6,375
Period of restriction on trade for shares issued to non-employee members of the board of directors under the Primoris Long-term Retention Plan										1 year
Accrued Dividend Equivalent Units		1,693								1,693
Aggregate purchase price up to which shares can be acquired under share repurchase program | $			$ 5,000					$ 23,000
Number of shares purchased and cancelled under the share repurchase program		207,800							100,000
Amount paid for shares purchased and cancelled under share repurchase program | $		$ 5,000							$ 2,800
Average cost of repurchased shares of stock (in dollars per share) | $ / shares		$ 24.02							$ 28.44
Preferred Stock
Preferred stock, authorized (in shares)		1,000,000								1,000,000	1,000,000
Par value of preferred stock (in dollars per share) | $ / shares		$ 0.0001								$ 0.0001	$ 0.0001
Preferred stock, shares outstanding		0								0	0
Warrants
Warrants outstanding (in shares)		0								0	0
Restricted Stock Units
Common Stock
Units granted	249,065
LTR Plan
Common Stock
Shares of common stock issued under the long-term incentive plan										85,907	96,828
Amount received in exchange for shares of common stock under a long term incentive plan | $										$ 1,440	$ 1,621
Percentage of average market closing prices used in determining number of common stock that could be purchased by participants										75.00%	75.00%
Discounted price from the average December market price at which shares purchased by participants in LTR Plan (as a percent)										25.00%
Equity Plan | Restricted Stock Units
Common Stock
Units granted										249,065
Accrued Dividend Equivalent Units		1,693								1,693
Shares of common stock reserved for issuance upon exercise of all future stock option grants, SARS and grants of restricted shares under the 2013 Equity Plan		1,953,559								1,953,559