Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 1,374,209	$ 247,612
Restricted cash	713	282
Accounts receivable, net of allowance for doubtful accounts and billing adjustments of $4.5 million and $3.9 million at 2013 and 2012, respectively	250,124	247,083
Deferred income tax assets	8,355	9,825
Prepaid expenses and other current assets	83,236	69,924
Total current assets	1,716,637	574,726
Goodwill	517,243	518,344
Property and equipment, net of accumulated depreciation and amortization of $376.8 million and $364.2 million at 2013 and 2012, respectively	248,778	260,389
Computer software, net of accumulated amortization of $511.0 million and $627.3 million at 2013 and 2012, respectively	243,138	226,917
Contract acquisition costs, net of accumulated amortization of $226.1 million and $216.0 million at 2013 and 2012, respectively	166,045	161,267
Other intangible assets, net of accumulated amortization of $66.2 million and $55.2 million at 2013 and 2012, respectively	118,923	130,054
Equity investments, net	94,447	87,764
Deferred income tax assets, net	5,873	5,334
Other assets	77,093	59,043
Total assets	3,188,177	2,023,838
Current liabilities:
Accounts payable	28,623	63,370
Current portion of obligations under capital leases	23,025	13,263
Current portion of long-term borrowings	21,032	27,361
Accrued salaries and employee benefits	17,783	26,243
Other current liabilities	117,961	100,282
Total current liabilities	208,424	230,519
Long-term borrowings, excluding current portion	1,260,625	174,859
Deferred income tax liabilities	66,885	48,074
Obligations under capital leases, excluding current portion	13,303	17,155
Other long-term liabilities	65,021	68,791
Total liabilities	1,614,258	539,398
Redeemable noncontrolling interest in consolidated subsidiary	39,101	39,505
Commitments and contingencies (Note 9)
Shareholders' equity:
Common stock - $0.10 par value. Authorized 600,000 shares; 202,813 and 202,471 issued at 2013 and 2012, respectively; 188,614 and 187,031 outstanding at 2013 and 2012, respectively	20,281	20,247
Additional paid-in capital	138,936	141,793
Accumulated other comprehensive income (loss), net	(9,950)	1,408
Treasury stock, at cost (14,199 and 15,440 shares at 2013 and 2012, respectively)	(259,661)	(287,301)
Retained earnings	1,626,300	1,549,063
Total shareholders' equity	1,515,906	1,425,210
Noncontrolling interests in consolidated subsidiaries	18,912	19,725
Total equity	1,534,818	1,444,935
Total liabilities and equity	$ 3,188,177	$ 2,023,838