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Investments in Marketable Securities (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Available-for-Sale
Cost	$ 103.1	$ 103.2
Unrealized Gains	12.0	33.3
Unrealized Losses	(2.1)	(1.1)
Fair Value	113.0	135.4
Trading
Cost	18.1	17.9
Unrealized Gains	4.9	4.6
Unrealized Losses	0	0
Fair Value	$ 23.0	$ 22.5

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Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax

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Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax

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

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

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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