Operations by Industry Segment and Geographic Area (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operations by Industry Segment and Geographic Area [Abstract]
Number of reportable segments	4
Segment Reporting Information [Line Items]
Revenues from external customers	$ 936,273	$ 908,641	$ 737,084
Intersegment revenues	74,803	73,856	55,367
Interest expense	339	190	339
Depreciation and amortization	20,935	18,005	17,444
Income taxes	19,096	19,337	16,649
Segment profit (loss)	34,108	41,741	34,523
Segment assets	1,416,344	1,429,023	1,279,616
Capital expenditures	26,018	36,130	11,336
Sales [Abstract]
Total external sales for reportable segments	830,907	819,353	675,109
Intersegment sales for reportable segments	74,635	73,856	55,367
Other sales	105,366	89,288	61,975
Elimination of intersegment sales	(74,635)	(73,856)	(55,367)
Total consolidated sales	936,273	908,641	737,084
Net income attributable to controlling interest [Abstract]
Total profit for reportable segments	64,188	79,970	62,102
Other losses	(30,080)	(38,229)	(27,579)
Net income attributable to non-controlling interest	(161)	(102)	(142)
Elimination of intersegment profit	(519)	(1,946)	(682)
Income (loss) from discontinued operations, net of tax	3,401	225	(1,269)
Gain on sale of subsidiary, net of tax	3,378	0	0
Total consolidated net income attributable to controlling interest	40,207	39,918	32,430
Assets [Abstract]
Total assets for reportable segments	1,023,669	1,020,120	912,142
Other assets	392,675	408,903	367,474
Elimination of intercompany profit in inventory	(4,410)	(3,890)	(1,944)
Elimination of intercompany receivables	(469,254)	(461,721)	(435,980)
Elimination of investment in subsidiaries	(186,556)	(160,988)	(119,562)
Other eliminations	(31,559)	(85,541)	(72,491)
Total assets	724,565	716,883	649,639
Interest expense [Abstract]
Total interest expense for reportable segments	84	22	202
Other interest expense	255	168	137
Total consolidated interest expense	339	190	339
Depreciation and amortization [Abstract]
Total depreciation and amortization for reportable segments	18,306	15,554	15,188
Other depreciation and amortization	2,629	2,451	2,256
Depreciation from discontinued operations	2,113	1,254	1,284
Total consolidated depreciation and amortization	23,048	19,259	18,728
Capital expenditures [Abstract]
Total capital expenditures for reportable segments	24,182	24,933	10,966
Other capital expenditures	1,836	11,197	370
Total consolidated capital expenditures	26,018	36,130	11,336
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	936,273	908,641	737,084
Long-lived assets by geographic region	182,839	188,018
United States [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	572,522	543,527	462,167
Sales [Abstract]
Total consolidated sales	572,522	543,527	462,167
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	572,522	543,527	462,167
Long-lived assets by geographic region	157,344	165,573
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets by geographic region	1,538	1,477
Canada [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	79,554	82,853	78,165
Sales [Abstract]
Total consolidated sales	79,554	82,853	78,165
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	79,554	82,853	78,165
Long-lived assets by geographic region	4,120	3,525
Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets by geographic region	9,630	9,520
Australia and Oceana [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	62,683	48,890	24,561
Sales [Abstract]
Total consolidated sales	62,683	48,890	24,561
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	62,683	48,890	24,561
Africa [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	60,811	65,472	60,396
Sales [Abstract]
Total consolidated sales	60,811	65,472	60,396
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	60,811	65,472	60,396
South America (excluding Brazil) [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	38,049	57,616	35,701
Sales [Abstract]
Total consolidated sales	38,049	57,616	35,701
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	38,049	57,616	35,701
Mexico [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	23,084	9,885	13,801
Sales [Abstract]
Total consolidated sales	23,084	9,885	13,801
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	23,084	9,885	13,801
Other European Countries [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	20,249	23,653	15,238
Sales [Abstract]
Total consolidated sales	20,249	23,653	15,238
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	20,249	23,653	15,238
Brazil [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	15,675	11,602	4,763
Sales [Abstract]
Total consolidated sales	15,675	11,602	4,763
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	15,675	11,602	4,763
Long-lived assets by geographic region	1,234	0
Russia [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	14,641	8,494	4,513
Sales [Abstract]
Total consolidated sales	14,641	8,494	4,513
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	14,641	8,494	4,513
Post-Soviet States (excluding Russia) [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	11,533	12,526	1,973
Sales [Abstract]
Total consolidated sales	11,533	12,526	1,973
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	11,533	12,526	1,973
Other Asian Countries [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	8,315	7,200	2,385
Sales [Abstract]
Total consolidated sales	8,315	7,200	2,385
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	8,315	7,200	2,385
Central America (excluding Mexico) [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	6,843	4,156	1,140
Sales [Abstract]
Total consolidated sales	6,843	4,156	1,140
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	6,843	4,156	1,140
Middle East [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	6,705	18,215	24,151
Sales [Abstract]
Total consolidated sales	6,705	18,215	24,151
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	6,705	18,215	24,151
China [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	6,687	2,923	414
Sales [Abstract]
Total consolidated sales	6,687	2,923	414
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	6,687	2,923	414
India [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	4,648	4,476	1,318
Sales [Abstract]
Total consolidated sales	4,648	4,476	1,318
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	4,648	4,476	1,318
West Indies [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	2,765	5,461	5,693
Sales [Abstract]
Total consolidated sales	2,765	5,461	5,693
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	2,765	5,461	5,693
Japan and South Korea [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	1,509	1,672	702
Sales [Abstract]
Total consolidated sales	1,509	1,672	702
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	1,509	1,672	702
Other [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	0	20	3
Sales [Abstract]
Total consolidated sales	0	20	3
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	0	20	3
Foreign [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	363,751	365,114	274,917
Sales [Abstract]
Total consolidated sales	363,751	365,114	274,917
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	363,751	365,114	274,917
Long-lived assets by geographic region	25,495	22,445
South Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets by geographic region	8,973	7,923
Asphalt Group [Member]
Segment Reporting Information [Line Items]
Number of business units	3
Revenues from external customers	234,562	260,404	226,419
Intersegment revenues	30,697	24,925	14,391
Interest expense	49	14	84
Depreciation and amortization	4,729	4,268	4,176
Income taxes	811	1,401	1,489
Segment profit (loss)	21,018	29,310	28,672
Segment assets	382,418	370,137	342,813
Capital expenditures	4,430	9,172	2,399
Sales [Abstract]
Total consolidated sales	234,562	260,404	226,419
Interest expense [Abstract]
Total consolidated interest expense	49	14	84
Capital expenditures [Abstract]
Total consolidated capital expenditures	4,430	9,172	2,399
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	234,562	260,404	226,419
Aggregate and Mining Group [Member]
Segment Reporting Information [Line Items]
Number of business units	7
Revenues from external customers	355,428	333,278	256,400
Intersegment revenues	25,776	25,219	24,294
Interest expense	32	3	52
Depreciation and amortization	7,381	6,932	6,714
Income taxes	1,582	1,834	2,436
Segment profit (loss)	34,687	31,493	16,578
Segment assets	399,832	359,931	335,008
Capital expenditures	9,376	8,138	4,271
Sales [Abstract]
Total consolidated sales	355,428	333,278	256,400
Interest expense [Abstract]
Total consolidated interest expense	32	3	52
Capital expenditures [Abstract]
Total consolidated capital expenditures	9,376	8,138	4,271
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	355,428	333,278	256,400
Mobile Asphalt Paving Group [Member]
Segment Reporting Information [Line Items]
Number of business units	3
Revenues from external customers	158,115	187,988	166,436
Intersegment revenues	16,474	18,629	13,471
Interest expense	3	5	66
Depreciation and amortization	3,262	2,788	2,806
Income taxes	(348)	1,009	993
Segment profit (loss)	10,721	26,485	23,234
Segment assets	157,675	155,676	137,744
Capital expenditures	3,239	6,678	3,951
Sales [Abstract]
Total consolidated sales	158,115	187,988	166,436
Interest expense [Abstract]
Total consolidated interest expense	3	5	66
Capital expenditures [Abstract]
Total consolidated capital expenditures	3,239	6,678	3,951
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	158,115	187,988	166,436
Underground Group [Member]
Segment Reporting Information [Line Items]
Number of business units	2
Revenues from external customers	82,802	37,683	25,854
Intersegment revenues	1,688	5,083	3,211
Interest expense	0	0	0
Depreciation and amortization	2,934	1,566	1,492
Income taxes	(230)	(550)	(481)
Segment profit (loss)	(2,238)	(7,318)	(6,382)
Segment assets	83,744	134,376	96,577
Capital expenditures	7,137	945	345
Sales [Abstract]
Total consolidated sales	82,802	37,683	25,854
Interest expense [Abstract]
Total consolidated interest expense	0	0	0
Capital expenditures [Abstract]
Total consolidated capital expenditures	7,137	945	345
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	82,802	37,683	25,854
All Others [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	105,366	89,288	61,975
Intersegment revenues	168	0	0
Interest expense	255	168	137
Depreciation and amortization	2,629	2,451	2,256
Income taxes	17,281	15,643	12,212
Segment profit (loss)	(30,080)	(38,229)	(27,579)
Segment assets	392,675	408,903	367,474
Capital expenditures	1,836	11,197	370
Sales [Abstract]
Total consolidated sales	105,366	89,288	61,975
Interest expense [Abstract]
Total consolidated interest expense	255	168	137
Capital expenditures [Abstract]
Total consolidated capital expenditures	1,836	11,197	370
Revenues from External Customers and Long-Lived Assets [Line Items]
Total consolidated sales	$ 105,366	$ 89,288	$ 61,975