|
Fair Value Measurements (Details) (USD $)
In Millions, unless otherwise specified |
Sep. 30, 2013
|
Dec. 31, 2012
|
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | $ 2,887.5 | $ 2,748.5 | ||||||||||||
| Trading securities: | ||||||||||||||
| Trading securities | 15.1 | [1] | 12.6 | [1] | ||||||||||
| Fair Value Measurements (Textuals) | ||||||||||||||
| Restricted investments | 88.1 | 102.6 | ||||||||||||
|
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Derivative assets: | ||||||||||||||
| Total assets measured at fair value | 2,905.4 | 2,764.6 | ||||||||||||
| Liabilities measured at fair value: | ||||||||||||||
| Other accrued liabilities | (3.4) | 0.1 | ||||||||||||
| Total liabilities measured at fair value | (3.4) | 0.1 | ||||||||||||
| Cash equivalents measured at fair value | 1,049.7 | 1,225.9 | ||||||||||||
| Restricted investments measured at fair value | 90.6 | 105.6 | ||||||||||||
| Short-term investments measured at fair value | 573.7 | 441.5 | ||||||||||||
| Long-term investments measured at fair value | 1,188.6 | 988.1 | ||||||||||||
| Prepaid expenses and other current assets measured at fair value | 2.8 | 3.5 | ||||||||||||
|
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Derivative assets: | ||||||||||||||
| Total assets measured at fair value | 1,370.6 | 1,692.5 | ||||||||||||
| Liabilities measured at fair value: | ||||||||||||||
| Other accrued liabilities | 0 | 0 | ||||||||||||
| Total liabilities measured at fair value | 0 | 0 | ||||||||||||
| Cash equivalents measured at fair value | 961.0 | 1,048.7 | ||||||||||||
| Restricted investments measured at fair value | 90.6 | 103.6 | ||||||||||||
| Short-term investments measured at fair value | 259.1 | 224.4 | ||||||||||||
| Long-term investments measured at fair value | 59.9 | 315.8 | ||||||||||||
| Prepaid expenses and other current assets measured at fair value | 0 | 0 | ||||||||||||
|
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Derivative assets: | ||||||||||||||
| Total assets measured at fair value | 1,534.8 | 1,072.1 | ||||||||||||
| Liabilities measured at fair value: | ||||||||||||||
| Other accrued liabilities | (3.4) | 0.1 | ||||||||||||
| Total liabilities measured at fair value | (3.4) | 0.1 | ||||||||||||
| Cash equivalents measured at fair value | 88.7 | 177.2 | ||||||||||||
| Restricted investments measured at fair value | 0 | 2.0 | ||||||||||||
| Short-term investments measured at fair value | 314.6 | 217.1 | ||||||||||||
| Long-term investments measured at fair value | 1,128.7 | 672.3 | ||||||||||||
| Prepaid expenses and other current assets measured at fair value | 2.8 | 3.5 | ||||||||||||
|
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Derivative assets: | ||||||||||||||
| Total assets measured at fair value | 0 | 0 | ||||||||||||
| Liabilities measured at fair value: | ||||||||||||||
| Other accrued liabilities | 0 | 0 | ||||||||||||
| Total liabilities measured at fair value | 0 | 0 | ||||||||||||
| Cash equivalents measured at fair value | 0 | 0 | ||||||||||||
| Restricted investments measured at fair value | 0 | 0 | ||||||||||||
| Short-term investments measured at fair value | 0 | 0 | ||||||||||||
| Long-term investments measured at fair value | 0 | 0 | ||||||||||||
| Prepaid expenses and other current assets measured at fair value | 0 | 0 | ||||||||||||
|
Foreign exchange contract [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Derivative assets: | ||||||||||||||
| Derivative assets | 2.8 | 3.5 | ||||||||||||
| Liabilities measured at fair value: | ||||||||||||||
| Derivative liabilities | (3.4) | 0.1 | ||||||||||||
|
Foreign exchange contract [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Derivative assets: | ||||||||||||||
| Derivative assets | 0 | 0 | ||||||||||||
| Liabilities measured at fair value: | ||||||||||||||
| Derivative liabilities | 0 | 0 | ||||||||||||
|
Foreign exchange contract [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Derivative assets: | ||||||||||||||
| Derivative assets | 2.8 | 3.5 | ||||||||||||
| Liabilities measured at fair value: | ||||||||||||||
| Derivative liabilities | (3.4) | 0.1 | ||||||||||||
|
Foreign exchange contract [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Derivative assets: | ||||||||||||||
| Derivative assets | 0 | 0 | ||||||||||||
| Liabilities measured at fair value: | ||||||||||||||
| Derivative liabilities | 0 | 0 | ||||||||||||
|
Asset-backed Securities [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 253.7 | 226.4 | ||||||||||||
|
Asset-backed Securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 253.7 | 226.4 | ||||||||||||
|
Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 253.7 | 226.4 | ||||||||||||
|
Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Certificates of deposit [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 24.8 | 41.9 | ||||||||||||
|
Certificates of deposit [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 24.9 | 42.5 | ||||||||||||
|
Certificates of deposit [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Certificates of deposit [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 24.9 | 42.5 | ||||||||||||
|
Certificates of deposit [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Commercial paper [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 11.5 | 11.6 | ||||||||||||
|
Commercial paper [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 11.5 | 22.4 | ||||||||||||
|
Commercial paper [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Commercial paper [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 11.5 | 22.4 | ||||||||||||
|
Commercial paper [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Corporate debt securities [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 769.1 | 535.6 | ||||||||||||
|
Corporate debt securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 769.1 | 535.6 | ||||||||||||
|
Corporate debt securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Corporate debt securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 769.1 | 535.6 | ||||||||||||
|
Corporate debt securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Foreign government debt securities [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 15.8 | 5.0 | ||||||||||||
|
Foreign government debt securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 15.8 | 5.0 | ||||||||||||
|
Foreign government debt securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Foreign government debt securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 15.8 | 5.0 | ||||||||||||
|
Foreign government debt securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Government-sponsored enterprise obligations [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 315.1 | 264.9 | ||||||||||||
|
Government-sponsored enterprise obligations [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 323.7 | 271.0 | ||||||||||||
|
Government-sponsored enterprise obligations [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 254.9 | ||||||||||||
|
Government-sponsored enterprise obligations [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 323.7 | 16.1 | ||||||||||||
|
Government-sponsored enterprise obligations [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Money market funds [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 1,044.1 | [2] | 1,145.2 | [3] | ||||||||||
|
Money market funds [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 1,044.1 | [2] | 1,145.2 | [3] | ||||||||||
|
Money market funds [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | [2] | 0 | [3] | ||||||||||
|
Money market funds [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | [2] | 0 | [3] | ||||||||||
|
Mutual funds [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 2.5 | [4] | 3.0 | [4] | ||||||||||
| Trading securities: | ||||||||||||||
| Trading securities | 15.1 | [5] | 12.6 | [5] | ||||||||||
|
Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 2.5 | [4] | 1.0 | [4] | ||||||||||
| Trading securities: | ||||||||||||||
| Trading securities | 15.1 | [5] | 12.6 | [5] | ||||||||||
|
Mutual funds [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | [4] | 2.0 | [4] | ||||||||||
| Trading securities: | ||||||||||||||
| Trading securities | 0 | [5] | 0 | [5] | ||||||||||
|
Mutual funds [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | [4] | 0 | [4] | ||||||||||
| Trading securities: | ||||||||||||||
| Trading securities | 0 | [5] | 0 | [5] | ||||||||||
|
Publicly-traded equity securities [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 126.7 | 2.9 | ||||||||||||
|
Publicly-traded equity securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 126.7 | 2.9 | ||||||||||||
|
Publicly-traded equity securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 126.7 | 2.9 | ||||||||||||
|
Publicly-traded equity securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Publicly-traded equity securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
US government securities [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 230.5 | 328.7 | ||||||||||||
|
US government securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 315.5 | 494.5 | ||||||||||||
|
US government securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 182.2 | 275.9 | ||||||||||||
|
US government securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 133.3 | 218.6 | ||||||||||||
|
US government securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 0 | 0 | ||||||||||||
|
Available-for-sale securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 2,887.5 | 2,748.5 | ||||||||||||
|
Available-for-sale securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 1,355.5 | 1,679.9 | ||||||||||||
|
Available-for-sale securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | 1,532.0 | 1,068.6 | ||||||||||||
|
Available-for-sale securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
|
||||||||||||||
| Available-for-sale securities: | ||||||||||||||
| Available-for-sale securities | $ 0 | $ 0 | ||||||||||||
|
||||||||||||||