UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
OPERATING ACTIVITIES:
Net income	$ 681,732	$ 534,470
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	21,068	15,150
Amortization	24,039	16,355
Provision for uncollectible accounts, net	8,181	6,843
Deferred income taxes	(3,312)	13,665
Stock-based compensation expense and other stock-based payments	56,804	34,370
Amortization of debt issuance costs	2,879	2,337
Amortization of debt discount	24,232	17,972
Changes in assets and liabilities:
Accounts receivable	(242,983)	(176,721)
Prepaid expenses and other current assets	(133,058)	(95,392)
Accounts payable, accrued expenses and other current liabilities	328,010	244,684
Other	8,907	253
Net cash provided by operating activities	776,499	613,986
INVESTING ACTIVITIES:
Purchase of investments	(4,226,562)	(2,989,951)
Proceeds from sale of investments	3,652,653	1,870,770
Additions to property and equipment	(36,481)	(28,423)
Acquisitions and other equity investments, net of cash acquired	(330,844)	(13,429)
Proceeds from settlement of foreign currency contracts	0	61,746
Payments on foreign currency contracts	(44,187)	0
Change in restricted cash	(546)	(2,987)
Net cash used in investing activities	(985,967)	(1,102,274)
FINANCING ACTIVITIES:
Proceeds from the issuance of convertible debt	980,000	1,000,000
Payment of debt issuance costs	(29)	(20,421)
Repurchase of common stock	(423,285)	(255,168)
Payments to purchase subsidiary shares from noncontrolling interests	(192,530)	(61,079)
Payments of stock issuance costs	(1,191)	0
Proceeds from exercise of stock options	72,810	1,693
Excess tax benefit from stock-based compensation	17,767	12,513
Net cash provided by financing activities	453,542	677,538
Effect of exchange rate changes on cash and cash equivalents	(18,209)	(9,300)
Net increase in cash and cash equivalents	225,865	179,950
Cash and cash equivalents, beginning of period	1,536,349	632,836
Cash and cash equivalents, end of period	1,762,214	812,786
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid during the period for income taxes	247,037	189,061
Cash paid during the period for interest	9,540	4,349
Non-cash fair value increase for redeemable noncontrolling interests	42,522	43,440
Non-cash financing activity for acquisitions	$ 1,545,042	$ 0