Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Jun. 30, 2020
Current assets:
Cash and cash equivalents	$ 73,751	$ 100,036
Accounts receivable, less allowances (March 31, 2021—$856 and June 30, 2020—$905)	158,099	160,671
Costs and estimated earnings in excess of billings on uncompleted contracts	37,964	59,548
Inventories	6,217	6,460
Income taxes receivable	11,443	3,919
Other current assets	7,013	4,526
Total current assets	294,487	335,160
Property, plant and equipment at cost:
Land and buildings	41,379	42,695
Construction equipment	95,526	94,154
Transportation equipment	52,467	55,864
Office equipment and software	41,196	39,356
Construction in progress	2,217	4,427
Total property, plant and equipment - at cost	232,785	236,496
Accumulated depreciation	(160,051)	(155,748)
Property, plant and equipment - net	72,734	80,748
Operating lease right-of-use assets	21,109	21,375
Goodwill	60,605	60,369
Other intangible assets, net of accumulated amortization	7,181	8,837
Deferred income taxes	4,513	5,988
Other assets	11,048	4,833
Total assets	471,677	517,310
Current liabilities:
Accounts payable	50,163	73,094
Billings on uncompleted contracts in excess of costs and estimated earnings	59,495	63,889
Accrued wages and benefits	21,983	16,205
Accrued insurance	7,437	7,301
Operating lease liabilities	5,199	7,568
Other accrued expenses	4,958	7,890
Total current liabilities	149,235	175,947
Deferred income taxes	34	61
Operating lease liabilities	20,651	19,997
Borrowings under senior secured revolving credit facility	0	9,208
Other liabilities	7,897	4,208
Total liabilities	177,817	209,421
Commitments and contingencies
Stockholders' equity:
Common stock—$.01 par value; 60,000,000 shares authorized; 27,888,217 shares issued as of March 31, 2021 and June 30, 2020; 26,519,217 and 26,141,528 shares outstanding as of March 31, 2021 and June 30, 2020	279	279
Additional paid-in capital	136,042	138,966
Retained earnings	185,901	206,402
Accumulated other comprehensive loss	(7,082)	(8,373)
Stockholders' equity	315,140	337,274
Less: Treasury stock, at cost — 1,369,000 shares as of March 31, 2021, and 1,746,689 shares as of June 30, 2020	(21,280)	(29,385)
Total stockholders' equity	293,860	307,889
Total liabilities and stockholders’ equity	$ 471,677	$ 517,310