Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income	$ 80.2	$ 110.6
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense	46.0	60.8
Depreciation, amortization, and accretion	47.5	48.1
Restructuring and other charges	1.4	122.4
Deferred income taxes	11.3	(44.5)
Gain on investments, net	(0.6)	(166.2)
Excess tax benefits from share-based compensation	(1.7)	(6.7)
Loss on disposal of fixed assets	0	0.8
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, net	54.2	(15.7)
Prepaid expenses and other assets	(21.8)	(15.7)
Accounts payable	(7.8)	19.0
Accrued compensation	(54.1)	(92.0)
Income taxes payable	14.1	73.1
Other accrued liabilities	(48.4)	(52.2)
Deferred revenue	99.0	82.8
Net cash provided by operating activities	219.3	124.6
Cash flows from investing activities:
Purchases of property and equipment	(44.2)	(57.4)
Purchases of available-for-sale investments	(398.8)	(327.1)
Proceeds from sales of available-for-sale investments	169.5	1,221.4
Proceeds from maturities of available-for-sale investments	57.3	79.3
Purchases of trading investments	(1.9)	(1.8)
Proceeds from sales of privately-held investments	0	2.5
Purchases of privately-held investments	(3.2)	(1.7)
Payments for business acquisitions, net of cash and cash equivalents acquired	0	(27.1)
Changes in restricted cash	0	24.9
Net cash (used in) provided by investing activities	(221.3)	913.0
Cash flows from financing activities:
Proceeds from issuance of common stock	31.8	101.2
Purchases and retirement of common stock	(402.4)	(905.8)
Purchase of equity forward contract	0	(300.0)
Issuance of long-term debt, net	594.6	346.5
Payment for capital lease obligation	0.4	(0.4)
Customer financing arrangements	0	8.0
Excess tax benefits from share-based compensation	1.7	6.7
Payment of cash dividends	(40.8)	0
Net cash provided by (used in) financing activities	185.3	(743.8)
Effect of foreign currency exchange rates on cash and cash equivalents	(12.1)	1.6
Net increase in cash and cash equivalents	171.2	295.4
Cash and cash equivalents at beginning of period	1,639.6	2,284.0
Cash and cash equivalents at end of period	$ 1,810.8	$ 2,579.4