Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

The cash outflow to acquire debt securities classified as available-for-sale securities, because they are not classified as either held-to-maturity securities or trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Glossary Investing Activities

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-Number 115

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-Number 95

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+ Details

Investments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Purchases of debt securities	$ 5.2	$ 24.3	$ 9.7	$ 24.3
Investments in available-for-sale securities
Available-for-sale securities, amortized cost	58.9		58.9		88.0
Available-for-sale securities, gross unrealized gains	0.2		0.2		0.4
Available-for-sale Securities, Gross Unrealized Losses	(0.3)		(0.3)		0
Current [Member] \| Federal government securities [Member]
Investments in available-for-sale securities
Available-for-sale securities, amortized cost	2.9		2.9
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale securities, fair value	2.9		2.9
Current [Member] \| U.S. corporate bonds [Member]
Investments in available-for-sale securities
Available-for-sale securities, amortized cost	2.0		2.0		4.1
Available-for-sale securities, gross unrealized gains	0		0		0
Available-for-sale Securities, Gross Unrealized Losses	0		0		0
Available-for-sale securities, fair value	2.0		2.0		4.1
Noncurrent [Member] \| Federal government securities [Member]
Investments in available-for-sale securities
Available-for-sale securities, amortized cost	25.4		25.4		32.0
Available-for-sale securities, gross unrealized gains	0.1		0.1		0.2
Available-for-sale Securities, Gross Unrealized Losses	0.2		0.2		0
Available-for-sale securities, fair value	25.3		25.3		32.2
Noncurrent [Member] \| U.S. corporate bonds [Member]
Investments in available-for-sale securities
Available-for-sale securities, amortized cost	17.7		17.7		19.5
Available-for-sale securities, gross unrealized gains	0.1		0.1		0.2
Available-for-sale Securities, Gross Unrealized Losses	0.1		0.1		0
Available-for-sale securities, fair value	17.7		17.7		19.7
Noncurrent [Member] \| Marketable equity securities [Member]
Investments in available-for-sale securities
Available-for-sale securities, amortized cost	10.9		10.9		32.4
Available-for-sale securities, gross unrealized gains	0		0		0
Available-for-sale Securities, Gross Unrealized Losses	0		0		0
Available-for-sale securities, fair value	10.9		10.9		32.4
Fair Value, Measurements, Recurring [Member]
Investments in available-for-sale securities
Available-for-sale securities, fair value	$ 58.8		$ 58.8		$ 88.4