Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 170,377	$ 156,371
Accounts receivable, net	244,175	243,636
Prepaids and other current assets	60,323	37,434
Deferred tax assets, net	15,628	22,994
Income tax receivable	19,879	17,847
Total current assets	510,382	478,282
Long-term assets
Property, plant and equipment, net	111,431	100,321
Goodwill	72,154	70,844
Contract acquisition costs, net	2,115	2,866
Deferred tax assets, net	34,823	32,512
Other long-term assets	74,699	62,153
Total long-term assets	295,222	268,696
Total assets	805,604	746,978
Current liabilities
Accounts payable	25,053	27,555
Accrued employee compensation and benefits	69,586	71,500
Other accrued expenses	23,723	33,816
Income taxes payable	11,041	10,051
Deferred tax liabilities, net	1,995	912
Deferred revenue	22,766	15,895
Other current liabilities	7,404	10,282
Total current liabilities	161,568	170,011
Long-term liabilities
Line of credit	88,000	64,000
Negative investment in deconsolidated subsidiary	76	76
Deferred tax liabilities, net	3,248	3,020
Deferred rent	8,565	6,729
Other long-term liabilities	45,228	32,895
Total long-term liabilities	145,117	106,720
Total liabilities	306,685	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 September 30, 2012 and December 31, 2011	0	0
Common stock - $0.01 par value; 150,000,000 shares authorized; 53,712,342 and 56,635,319 shares outstanding as of September 30, 2012 and December 31, 2011, respectively	537	566
Additional paid-in capital	349,131	350,386
Treasury stock at cost: 28,339,911 and 25,416,934 shares as of September 30, 2012 and December 31, 2011, respectively	(404,307)	(357,267)
Accumulated other comprehensive income (loss)	19,123	(5,474)
Retained earnings	520,409	470,776
Noncontrolling interest	14,026	11,260
Total stockholders' equity	498,919	470,247
Total liabilities and stockholders' equity	$ 805,604	$ 746,978