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Debt - Narrative (Details)		3 Months Ended		6 Months Ended		12 Months Ended
Debt - Narrative (Details)	Oct. 02, 2019 USD ($)	Jun. 30, 2020 USD ($) entity	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) entity numberOfLoans	Jun. 30, 2019 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 05, 2019 USD ($)
Debt Instrument [Line Items]
Long-term debt		$ 430,451,000		$ 430,451,000							$ 443,035,000
Amortization of debt issuance costs		740,000	$ 518,000	1,491,000	$ 1,037,000
Finance lease liabilities		$ 659,000		$ 659,000							764,000
Number of entities \| entity		2		2
Ownership interest in subsidiaries		50.00%		50.00%
Paycheck protection loans received, CARES Act \| numberOfLoans				3
Paycheck protection program loan amount, CARES Act		$ 9,800,000		$ 9,800,000
Plateau Excavation
Debt Instrument [Line Items]
Liabilities incurred	$ 10,000,000
Tealstone Construction
Debt Instrument [Line Items]
Promissory notes issued to the sellers		5,000,000		5,000,000
Deferred cash payments due		7,500,000		$ 7,500,000
Secured Debt
Debt Instrument [Line Items]
Fixed charge ratio minimum				1.20
Secured Debt \| Credit Agreement
Debt Instrument [Line Items]
Debt instrument face amount	475,000,000
Secured Debt \| Credit Facility
Debt Instrument [Line Items]
Long-term debt		410,000,000		$ 410,000,000							420,000,000
Secured Debt \| Term Loan Facility
Debt Instrument [Line Items]
Long-term debt		$ 390,000,000		$ 390,000,000							400,000,000
Weighted average interest rate		5.80%		5.80%
Notes Payable, Other Payables \| Plateau Excavation
Debt Instrument [Line Items]
Liabilities incurred	$ 10,000,000
Stated interest rate	8.00%
Notes Payable, Other Payables \| Tealstone Construction
Debt Instrument [Line Items]
Long-term debt		$ 0		$ 0							$ 12,230,000
Notes Payable, Other Payables \| Notes payable for transportation and construction equipment and other \| Minimum
Debt Instrument [Line Items]
Stated interest rate		2.99%		2.99%
Debt instrument, term				3 years
Notes Payable, Other Payables \| Notes payable for transportation and construction equipment and other \| Maximum
Debt Instrument [Line Items]
Stated interest rate		6.92%		6.92%
Debt instrument, term				5 years
Revolving Credit Facility \| Secured Debt \| Term Loan Facility
Debt Instrument [Line Items]
Debt instrument face amount	$ 400,000,000
Revolving Credit Facility \| Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity	75,000,000
Debt instrument, base interest rate				4.25%
Debt instrument, LIBOR interest rate				0.19%
Line of credit, remaining borrowing capacity		$ 55,000,000		$ 55,000,000
Weighted average interest rate		7.15%		7.15%
Revolving Credit Facility \| Line of Credit \| Revolving Credit Facility \| Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate				3.50%
Revolving Credit Facility \| Line of Credit \| Revolving Credit Facility \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate				4.50%
Swing Line Loan \| Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity	$ 15,000,000
Interest Rate Swap \| Secured Debt
Debt Instrument [Line Items]
Derivative, notional amount		$ 350,000,000		$ 350,000,000								$ 350,000,000
Forecast \| Secured Debt \| Term Loan Facility
Debt Instrument [Line Items]
Periodic payments						$ 220,000,000	$ 50,000,000	$ 50,000,000	$ 50,000,000	$ 30,000,000
October 1, 2019 - June 30, 2020 \| Secured Debt \| Credit Agreement
Debt Instrument [Line Items]
Leverage ratio maximum				4.00
July 1, 2020 - September 30, 2020 \| Secured Debt \| Credit Agreement
Debt Instrument [Line Items]
Leverage ratio maximum				3.75
October 1, 2020 - March 31, 2021 \| Secured Debt \| Credit Agreement
Debt Instrument [Line Items]
Leverage ratio maximum				3.50
April 1, 2021 - June 30, 2021 \| Secured Debt \| Credit Agreement
Debt Instrument [Line Items]
Leverage ratio maximum				3.25
October 1, 2021 - December 31, 2021 \| Secured Debt \| Credit Agreement
Debt Instrument [Line Items]
Leverage ratio maximum				3.00