UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
OPERATING ACTIVITIES:
Net income	$ 1,134,442,000	$ 833,175,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	23,321,000	14,801,000
Amortization	24,192,000	25,286,000
Provision for uncollectible accounts, net	11,287,000	7,641,000
Deferred income taxes	16,446,000	34,170,000
Stock-based compensation expense and other stock-based payments	52,042,000	40,756,000
Amortization of debt issuance costs	3,790,000	1,676,000
Amortization of debt discount	28,831,000	15,944,000
Loss on early extinguishment of debt	0	32,000
Changes in assets and liabilities:
Accounts receivable	(232,660,000)	(202,087,000)
Prepaid expenses and other current assets	(97,057,000)	5,981,000
Accounts payable, accrued expenses and other current liabilities	318,054,000	292,160,000
Other	6,243,000	(9,564,000)
Net cash provided by operating activities	1,288,931,000	1,059,971,000
INVESTING ACTIVITIES:
Purchase of investments	(4,790,106,000)	(2,230,661,000)
Proceeds from sale of investments	3,069,242,000	1,529,998,000
Additions to property and equipment	(38,950,000)	(29,770,000)
Acquisitions and other equity investments, net of cash acquired	(13,871,000)	(67,973,000)
Proceeds from settlement of foreign currency contracts	78,828,000	5,205,000
Payments on foreign currency contracts	(2,222,000)	(42,032,000)
Change in restricted cash	(3,474,000)	(2,920,000)
Net cash used in investing activities	(1,700,553,000)	(838,153,000)
FINANCING ACTIVITIES:
Proceeds from the issuance of convertible debt	1,000,000,000	0
Payment of debt issuance costs	(20,916,000)	0
Payments related to the conversion of convertible debt	(1,000)	(213,000)
Repurchase of common stock	(255,397,000)	(162,369,000)
Payments to purchase subsidiary shares from noncontrolling interests	(61,079,000)	(12,986,000)
Proceeds from exercise of stock options	2,655,000	3,991,000
Excess tax benefit from stock-based compensation	12,911,000	14,996,000
Net cash provided by (used in) financing activities	678,173,000	(156,581,000)
Effect of exchange rate changes on cash and cash equivalents	(917,000)	(3,038,000)
Net increase in cash and cash equivalents	265,634,000	62,199,000
Cash and cash equivalents, beginning of period	632,836,000	358,967,000
Cash and cash equivalents, end of period	898,470,000	421,166,000
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid during the period for income taxes	205,256,000	99,376,000
Cash paid during the period for interest	13,463,000	7,443,000
Non-cash fair value increase for redeemable noncontrolling interests	$ 59,255,000	$ 41,327,000