Consolidated Condensed Statements of Stockholders Equity (Unaudited) (USD $) In Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2009	$ 274,907	$ 219	$ 76,477	$ 196,480	$ 1,731
Balance (in Shares) at Dec. 31, 2009		21,885
Issuance of comm on stock from share-based payment arrangement exercises	234		234
Issuance of comm on stock from share-based payment arrangement exercises (in Shares)		49
Tax benefits from share-based payment arrangement exercises	273		273
Share-based payment arrangement compensation expense	460		460
Income before income taxes attributable to noncontrolling interest	57				57
Noncontrolling interest distributions and other, net	159				159
Net income	9,050			9,050
Balance at Jun. 30, 2010	285,140	219	77,444	205,530	1,947
Balance (in Shares) at Jun. 30, 2010		21,934
Issuance of comm on stock from share-based payment arrangement exercises	69	1	68
Issuance of comm on stock from share-based payment arrangement exercises (in Shares)		16
Tax benefits from share-based payment arrangement exercises	112		112
Share-based payment arrangement compensation expense	804		804
Dividends on common stock	(877)			(877)
Income before income taxes attributable to noncontrolling interest	574				574
Noncontrolling interest distributions and other, net	(610)				(610)
Net income	10,692			10,692
Balance at Dec. 31, 2010	295,904	220	78,428	215,345	1,911
Balance (in Shares) at Dec. 31, 2010		21,950
Issuance of comm on stock from share-based payment arrangement exercises	137		137
Issuance of comm on stock from share-based payment arrangement exercises (in Shares)		27
Issuance of common stock from vesting of performance unit awards (in Shares)		8
Tax benefits from share-based payment arrangement exercises	164		164
Share-based payment arrangement compensation expense	595		595
Dividends on common stock	(878)			(878)
Income before income taxes attributable to noncontrolling interest	390				390
Noncontrolling interest distributions and other, net	131				131
Net income	10,289			10,289
Balance at Jun. 30, 2011	$ 306,732	$ 220	$ 79,324	$ 224,756	$ 2,432
Balance (in Shares) at Jun. 30, 2011		21,985