Note 9 - Construction Joint Ventures (Details Textual) $ in Thousands	3 Months Ended									6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)		Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)		Dec. 31, 2020 USD ($)
Contract Value of Active Construction Joint Venture Projects	$ 2,600,000											$ 2,600,000
Contract with Customer, Liability, Total	173,286				$ 200,041	[1]						173,286	$ 200,041	[1]
Revenue from Contract with Customer, Including Assessed Tax	789,213	$ 1,008,910	$ 849,247	$ 653,886	805,651		$ 1,062,129	$ 964,172	$ 669,913	$ 1,503,133	$ 2,512,043	3,301,256	3,501,865		$ 3,562,459
Retained Earnings (Accumulated Deficit), Total	481,384	$ 465,134	$ 401,667	$ 388,756	410,831					$ 401,667	$ 465,134	481,384	410,831
Unconsolidated Construction Joint Venture Net Income (Loss)												(19,676)	(765)		(51,486)
Unconsolidated Construction Corporate Joint Venture [Member]
Contract with Customer, Liability, Total	73,400											73,400
Minimum [Member] | Unconsolidated Construction Corporate Joint Venture [Member]
Contract with Customer, Liability, Total	$ 200											$ 200
Equity Method Investment, Ownership Percentage	23.00%											23.00%
Maximum [Member] | Unconsolidated Construction Corporate Joint Venture [Member]
Contract with Customer, Liability, Total	$ 34,600											$ 34,600
Equity Method Investment, Ownership Percentage	50.00%											50.00%
Consolidated Construction Corporate Joint Venture [Member]
Contract Value of Active Construction Joint Venture Projects	$ 1,000,000											$ 1,000,000
Consolidated Construction Corporate Joint Venture [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Number of Active Joint Venture Projects	10											10
Contract Value of Active Construction Joint Venture Projects	$ 1,800,000											$ 1,800,000
Contract with Customer, Liability, Total	120,000											120,000
Revenue from Contract with Customer, Including Assessed Tax												437,100	405,100		312,500
Net Cash Provided by (Used in) Continuing Operations, Total												(5,700)	(4,100)		(3,000)
Consolidated Construction Corporate Joint Venture [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Minimum [Member]
Contract Value of Active Construction Joint Venture Projects	2,500											2,500
Contract with Customer, Liability, Total	1,300											$ 1,300
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage												50.00%
Consolidated Construction Corporate Joint Venture [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Maximum [Member]
Contract Value of Active Construction Joint Venture Projects	433,400											$ 433,400
Contract with Customer, Liability, Total	$ 24,600											$ 24,600
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage												70.00%
Unconsolidated Construction Corporate Joint Venture [Member]
Number of Active Joint Venture Projects	7											7
Contract Value of Active Construction Joint Venture Projects	$ 8,900,000											$ 8,900,000
Affirmative Claim Recovery Estimate	104,300				103,800							104,300	103,800
Back Charge Claims	2,700				10,700							2,700	10,700
Retained Earnings (Accumulated Deficit), Total	14,000				28,600							14,000	28,600
Unconsolidated Construction Corporate Joint Venture [Member] | Minimum [Member]
Contract Value of Active Construction Joint Venture Projects	12,300											12,300
Unconsolidated Construction Corporate Joint Venture [Member] | Maximum [Member]
Contract Value of Active Construction Joint Venture Projects	3,800,000											3,800,000
Line Item Joint Venture [Member]
Contract Value of Active Construction Joint Venture Projects	206,700											206,700
Contract with Customer, Liability, Total	37,500											37,500
Revenue from Contract with Customer, Including Assessed Tax												35,400	67,800		$ 80,800
Unconsolidated Construction Joint Venture Net Income (Loss)												327,700
Performance Guarantee [Member] | Unconsolidated Construction Corporate Joint Venture [Member]
Guarantor Obligations, Current Carrying Value	64,700				$ 82,100							64,700	$ 82,100
Performance Guarantee [Member] | Unconsolidated Construction Corporate Joint Venture [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted	110,900											110,900
Performance Guarantee [Member] | Co-venturer [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted	135,500											135,500
Unconsolidated Construction Corporate Joint Venture [Member] | Performance Guarantee [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 246,400											$ 246,400

[1] These balances do not include amounts held for sale (see Note 2).