Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenues	$ 245,645	$ 251,237	$ 798,466	$ 905,673
Cost of revenues	230,754	253,851	727,981	847,797
Gross profit (loss)	14,891	(2,614)	70,485	57,876
Selling, general and administrative expenses	20,753	18,596	63,852	56,548
Operating income (loss)	(5,862)	(21,210)	6,633	1,328
Other income (expense):
Interest expense	(643)	(833)	(2,080)	(1,573)
Interest income	130	73	234	111
Other	370	(51)	384	3
Income (loss) before income tax expense	(6,005)	(22,021)	5,171	(131)
Provision (benefit) for federal, state and foreign income taxes	(852)	(8,521)	1,968	(1,223)
Net income (loss)	(5,153)	(13,500)	3,203	1,092
Less: Net income attributable to noncontrolling interest	$ 0	$ 321	$ 0	$ 321
Basic earnings (loss) per common share (US$ per share)	$ (0.19)	$ (0.52)	$ 0.12	$ 0.03
Diluted earnings (loss) per common share (US$ per share)	$ (0.19)	$ (0.52)	$ 0.12	$ 0.03
Weighted average common shares outstanding:
Basic (shares)	26,817	26,594	26,747	26,511
Diluted (shares)	26,817	26,594	27,054	26,838