Consolidated Balance Sheets (USD $)	Mar. 31, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 172,761	$ 156,371
Accounts receivable, net	244,212	243,636
Prepaids and other current assets	46,611	37,434
Deferred tax assets, net	19,886	22,994
Income tax receivable	5,856	17,847
Total current assets	489,326	478,282
Long-term assets
Property, plant and equipment, net	98,645	100,321
Goodwill	74,069	70,844
Contract acquisition costs, net	2,624	2,866
Deferred tax assets, net	31,652	32,512
Other long-term assets	74,799	62,153
Total long-term assets	281,789	268,696
Total assets	771,115	746,978
Current liabilities
Accounts payable	20,793	27,555
Accrued employee compensation and benefits	70,019	71,500
Other accrued expenses	29,778	33,816
Income taxes payable	8,695	10,051
Deferred tax liabilities, net	1,832	912
Deferred revenue	13,546	15,895
Other current liabilities	5,161	10,282
Total current liabilities	149,824	170,011
Long-term liabilities
Line of credit	85,000	64,000
Negative investment in deconsolidated subsidiary	76	76
Deferred tax liabilities, net	3,242	3,020
Deferred rent	7,516	6,729
Other long-term liabilities	45,229	32,895
Total long-term liabilities	141,063	106,720
Total liabilities	290,887	276,731
Commitments and contingencies (Note 10)	0	0
Stockholders' equity
Preferred stock - $0.01 par value: 10,000,000 shares authorized; zero shares outstanding as of March 31, 2012 and December 31, 2011	0	0
Common stock - $0.01 par value; 150,000,000 shares authorized; 55,678,427 and 56,635,319 shares outstanding as of March 31, 2012 and December 31, 2011, respectively	556	566
Additional paid-in capital	342,895	350,386
Treasury stock at cost: 26,373,826 and 25,416,934 shares as of March 31, 2012 and December 31, 2011, respectively	(373,440)	(357,267)
Accumulated other comprehensive income (loss)	10,707	(5,474)
Retained earnings	486,657	470,776
Noncontrolling interest	12,853	11,260
Total stockholders' equity	480,228	470,247
Total liabilities and stockholders' equity	$ 771,115	$ 746,978