CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CONSOLIDATED STATEMENTS OF INCOME
Net service revenues	$ 348,524	$ 339,853	$ 335,295
Cost of service revenues (excluding depreciation and amortization)	180,824	167,066	152,545
Gross margin	167,700	172,787	182,750
General and administrative expenses:
Salaries and benefits	98,441	97,526	91,309
Other	40,715	40,700	39,784
Total general and administrative expenses	139,156	138,226	131,093
Operating income	28,544	34,561	51,657
Interest expense, net	(104)	(180)	(266)
Income before income taxes	28,440	34,381	51,391
Income tax expense	(11,156)	(13,579)	(20,678)
Net income	$ 17,284	$ 20,802	$ 30,713
Per share amounts-basic:
Average shares outstanding (in shares)	9,285	9,278	9,123
Net income (in dollars per share)	$ 1.86	$ 2.24	$ 3.37
Per share amounts-diluted:
Average shares outstanding (in shares)	9,324	9,360	9,352
Net income (in dollars per share)	$ 1.85	$ 2.22	$ 3.28