Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Segment	Jun. 30, 2012
Segment Information [Abstract]
Number of reportable segments			4
Segment Reporting Information [Line Items]
Net sales to external customers	$ 248,127	$ 238,275	$ 495,960	$ 490,243
Gross profit	55,442	53,061	114,009	111,657
Gross profit (in hundredths)	22.30%	22.30%	23.00%	22.80%
Segment profit (loss)	11,289	10,468	25,153	21,965
Reconciliation of total segment profits to the Company's consolidated totals [Abstract]
Total segment profits	11,289	10,468	25,153	21,965
Elimination of intersegment profit	(136)	(887)	(750)	(360)
Net income from continuing operations	11,153	9,581	24,403	21,605
Income from discontinued operations, net of tax	0	848	0	1,082
Net income attributable to non-controlling interest in subsidiary	(61)	(63)	(140)	(76)
Net income attributable to controlling interest	11,092	10,366	24,263	22,611
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intersegment sales	24,749	19,255	44,678	37,919
Asphalt Group [Member]
Segment Reporting Information [Line Items]
Number of business units			3
Net sales to external customers	63,153	59,431	134,703	128,102
Gross profit	11,878	11,775	32,032	28,171
Gross profit (in hundredths)	18.80%	19.80%	23.80%	22.00%
Segment profit (loss)	4,061	3,902	15,202	11,293
Reconciliation of total segment profits to the Company's consolidated totals [Abstract]
Total segment profits	4,061	3,902	15,202	11,293
Asphalt Group [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intersegment sales	2,572	6,140	7,746	14,050
Aggregate and Mining Group [Member]
Segment Reporting Information [Line Items]
Number of business units			7
Net sales to external customers	99,884	94,860	190,646	186,164
Gross profit	25,615	25,818	48,656	49,555
Gross profit (in hundredths)	25.60%	27.20%	25.50%	26.60%
Segment profit (loss)	11,141	11,567	20,198	21,138
Reconciliation of total segment profits to the Company's consolidated totals [Abstract]
Total segment profits	11,141	11,567	20,198	21,138
Aggregate and Mining Group [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intersegment sales	14,782	6,320	23,037	13,316
Mobile Asphalt Paving Group [Member]
Segment Reporting Information [Line Items]
Number of business units			3
Net sales to external customers	45,750	45,160	93,041	87,153
Gross profit	11,171	10,151	21,730	20,756
Gross profit (in hundredths)	24.40%	22.50%	23.40%	23.80%
Segment profit (loss)	4,608	4,082	8,829	8,003
Reconciliation of total segment profits to the Company's consolidated totals [Abstract]
Total segment profits	4,608	4,082	8,829	8,003
Mobile Asphalt Paving Group [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intersegment sales	5,129	6,265	11,575	9,482
Underground Group [Member]
Segment Reporting Information [Line Items]
Number of business units			2
Net sales to external customers	17,094	19,230	31,800	41,288
Gross profit	2,232	2,054	2,507	5,137
Gross profit (in hundredths)	13.10%	10.70%	7.90%	12.40%
Segment profit (loss)	(768)	(873)	(3,149)	(1,046)
Reconciliation of total segment profits to the Company's consolidated totals [Abstract]
Total segment profits	(768)	(873)	(3,149)	(1,046)
Underground Group [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intersegment sales	2,266	418	2,320	958
All Others [Member]
Segment Reporting Information [Line Items]
Net sales to external customers	22,246	19,594	45,770	47,536
Gross profit	4,546	3,263	9,084	8,038
Gross profit (in hundredths)	20.40%	16.70%	19.80%	16.90%
Segment profit (loss)	(7,753)	(8,210)	(15,927)	(17,423)
Reconciliation of total segment profits to the Company's consolidated totals [Abstract]
Total segment profits	(7,753)	(8,210)	(15,927)	(17,423)
All Others [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intersegment sales	$ 0	$ 112	$ 0	$ 113