Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net income	$ 803.0	$ 720.8
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	159.6	95.5
Provision for doubtful accounts	(1.4)	6.2
Deferred income taxes	(36.9)	2.4
Stock-based compensation expense	95.2	69.4
Excess tax benefits on stock-based compensation plans	(15.3)	(12.0)
Other	8.7	(3.3)
Changes in assets and liabilities:
Trade accounts receivable	(185.7)	(161.2)
Other current assets	(20.6)	(52.6)
Other noncurrent assets	(50.3)	19.4
Accounts payable	19.4	8.1
Other current and noncurrent liabilities	(130.3)	(127.1)
Net cash provided by operating activities	645.4	565.6
Cash flows from investing activities:
Purchases of property and equipment	(133.6)	(82.0)
Purchases of investments	(1,565.8)	(1,407.6)
Proceeds from maturity or sale of investments	845.9	809.9
Business combinations, net of cash acquired	0.0	(11.5)
Net cash (used in) investing activities	(853.5)	(691.2)
Cash flows from financing activities:
Issuance of common stock under stock-based compensation plans	68.5	49.8
Excess tax benefits on stock-based compensation plans	15.3	12.0
Repurchases of common stock	(214.0)	(161.8)
Repayment of term loan borrowings and capital lease obligations	26.2	0.0
Net change in notes outstanding under revolving credit facility	(550.0)	0.0
Net cash (used in) financing activities	(706.4)	(100.0)
Effect of exchange rate changes on cash and cash equivalents	(6.3)	5.0
(Decrease) in cash and cash equivalents	(920.8)	(220.6)
Cash and cash equivalents, beginning of year	2,010.1	2,213.0
Cash and cash equivalents, end of period	$ 1,089.3	$ 1,992.4