Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets
Cash and cash equivalents	$ 150,623	$ 164,485
Accounts receivable, net	244,823	251,206
Prepaids and other current assets	55,231	58,702
Deferred tax assets, net	8,927	14,169
Income tax receivable	9,790	14,982
Total current assets	469,394	503,544
Long-term assets
Property, plant and equipment, net	108,523	112,276
Goodwill	93,577	94,679
Contract acquisition costs, net	1,321	1,860
Deferred tax assets, net	46,384	35,429
Other long-term assets	91,439	99,385
Total long-term assets	341,244	343,629
Total assets	810,638	847,173
Current liabilities
Accounts payable	23,512	23,494
Accrued employee compensation and benefits	68,853	71,621
Other accrued expenses	27,185	29,056
Income taxes payable	4,055	12,650
Deferred tax liabilities, net	355	341
Deferred revenue	25,866	26,892
Other current liabilities	10,484	7,351
Total current liabilities	160,310	171,405
Long-term liabilities
Line of credit	110,000	108,000
Deferred tax liabilities, net	2,507	3,029
Deferred rent	9,354	8,589
Other long-term liabilities	54,767	55,813
Total long-term liabilities	176,628	175,431
Total liabilities	336,938	346,836
Commitments and contingencies (Note 10)
Stockholders' equity
Preferred stock - $0.01 par value: 10,000,000 shares authorized; zero shares outstanding as of June 30, 2013 and December 31, 2012	0	0
Common stock - $0.01 par value; 150,000,000 shares authorized; 51,346,419 and 52,288,567 shares outstanding as of June 30, 2013 and December 31, 2012, respectively	513	522
Additional paid-in capital	347,737	350,714
Treasury stock at cost: 30,705,834 and 29,763,686 shares as of June 30, 2013 and December 31, 2012, respectively	(452,815)	(428,716)
Accumulated other comprehensive income	(5,186)	22,981
Retained earnings	571,067	540,791
Noncontrolling interest	12,384	14,045
Total stockholders' equity	473,700	500,337
Total liabilities and stockholders' equity	$ 810,638	$ 847,173