CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
OPERATING ACTIVITIES:
Net income	$ 1,892,798	$ 1,424,037	$ 1,059,131
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	48,365	32,818	20,648
Amortization	69,610	32,323	33,176
Provision for uncollectible accounts, net	16,451	16,094	9,331
Deferred income tax expense (benefit)	(11,104)	19,596	44,747
Stock-based compensation and other stock based payments	142,098	72,035	66,194
Amortization of debt issuance costs	7,898	5,212	2,360
Amortization of debt discount	55,718	39,820	21,414
Loss on early extinguishment of debt	26,661	0	32
Changes in assets and liabilities:
Accounts receivable	(111,572)	(105,277)	(125,793)
Prepaid expenses and other current assets	(6,909)	(40,793)	12,213
Accounts payable, accrued expenses and other current liabilities	182,163	256,021	210,325
Other	(10,741)	33,864	(11,966)
Net cash provided by operating activities	2,301,436	1,785,750	1,341,812
INVESTING ACTIVITIES:
Purchase of investments	(9,955,800)	(6,352,495)	(3,005,397)
Proceeds from sale of investments	8,291,283	4,799,412	2,229,563
Additions to property and equipment	(84,445)	(55,158)	(46,833)
Acquisitions and other equity investments, net of cash acquired	(331,918)	(33,861)	(68,192)
Proceeds from foreign currency contracts	3,266	86,159	31,045
Payments on foreign currency contracts	(81,870)	(4,014)	(42,032)
Change in restricted cash	(2,783)	(2,756)	(2,922)
Net cash used in investing activities	(2,162,267)	(1,562,713)	(904,768)
FINANCING ACTIVITIES:
Proceeds from the issuance of convertible senior notes	980,000	1,000,000	0
Payment of debt issuance costs	(1,018)	(20,916)	0
Payments related to conversion of senior notes	(414,569)	(1)	(213)
Repurchase of common stock	(883,515)	(257,021)	(163,171)
Payments to purchase subsidiary shares from noncontrolling interests	(192,530)	(61,079)	(12,986)
Proceeds from exercise of stock options	91,607	2,683	4,302
Proceeds from the termination of conversion spread hedges	19	0	0
Payments of stock issuance costs	(1,191)	0	0
Excess tax benefit from stock-based compensation	17,686	5,189	21,041
Net cash (used in) provided by financing activities	(403,511)	668,855	(151,027)
Effect of exchange rate changes on cash and cash equivalents	17,987	11,621	(12,148)
Net (decrease) increase in cash and cash equivalents	(246,355)	903,513	273,869
Cash and cash equivalents, beginning of period	1,536,349	632,836	358,967
Cash and cash equivalents, end of period	1,289,994	1,536,349	632,836
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid during the period for income taxes	391,169	300,539	232,762
Cash paid during the period for interest	20,954	13,933	7,573
Non-cash fair value increase for redeemable noncontrolling interests	42,522	84,693	91,743
Non-cash financing activity for acquisitions	$ 1,546,748	$ 0	$ 0