CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Thousands, except Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) [Abstract]
Revenues	$ 176,206	$ 170,487	$ 508,770	$ 525,009
Cost of services (exclusive of depreciation and amortization of $8,973, $9,309, $26,967, and $29,471, respectively, included below)	129,588	119,686	377,513	370,539
Selling, general & administrative expenses	14,185	17,420	49,724	53,358
Depreciation and amortization	12,467	12,772	37,343	39,666
Operating income	19,966	20,609	44,190	61,446
Gain on sale of investment	0	0	0	(1,163)
Interest expense	3,221	3,487	9,809	10,521
Income before income taxes	16,745	17,122	34,381	52,088
Income tax expense	7,281	6,598	15,004	20,312
Net income	$ 9,464	$ 10,524	$ 19,377	$ 31,776
Earnings per share:
Basic (in dollars per share)	$ 0.28	$ 0.31	$ 0.57	$ 0.93
Diluted (in dollars per share)	$ 0.28	$ 0.30	$ 0.56	$ 0.91
Weighted average common shares and equivalents:
Basic (in shares)	33,534	34,231	33,815	34,103
Diluted (in shares)	34,178	34,964	34,525	34,939