Condensed Consolidated Statements Of Equity (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss)[Member]	Noncontrolling Interests [Member]	Total
Balance - value at Dec. 31, 2010	$ 6	$ 266,329	$ 12,261	$ 357	$ (2,128)	$ 276,825
Balance - shares at Dec. 31, 2010	58,770,369
Share-based compensation, Value		843				843
Share-based compensation, Shares	57,215
Vesting of restricted stock units, including impact of shares withheld for taxes, value		(250)				(250)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares	81,387
Exercise of stock options, Value		27				27
Exercise of stock options, Shares	6,278
Dividends declared and paid			(2,236)			(2,236)
Dividend equivalents paid on restricted stock units			(11)			(11)
Excess income tax benefit from share based compensation		52				52
Acquisition of noncontrolling interest in NASDI, LLC		(40)			1,973	1,933
Net income			4,098		468	4,566
Other comprehensive income-net of tax				(248)		(248)
Balance - value at Jun. 30, 2011	6	266,961	14,112	109	313	281,501
Balance - shares at Jun. 30, 2011	58,915,249
Balance - value at Dec. 31, 2011	6	267,918	24,042	3	568	292,537
Balance - shares at Dec. 31, 2011	58,999,404
Share-based compensation, Value		1,714				1,714
Share-based compensation, Shares	122,136
Vesting of restricted stock units, including impact of shares withheld for taxes, value		(212)				(212)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares	81,640
Exercise of stock options, Value		75				75
Exercise of stock options, Shares	17,242
Dividends declared and paid			(2,482)			(2,482)
Dividend equivalents paid on restricted stock units			(22)			(22)
Distributions paid to noncontrolling interests					(134)	(134)
Excess income tax benefit from share based compensation		118				118
Net income			5,505		(206)	5,299
Other comprehensive income-net of tax				(1,292)		(1,292)
Balance - value at Jun. 30, 2012	$ 6	$ 269,613	$ 27,043	$ (1,289)	$ 228	$ 295,601
Balance - shares at Jun. 30, 2012	59,220,422