Investments (Details 1) (Debt Securities [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Debt Securities [Member]
Contractual maturities for available-for-sale securities
Due in one year or less, Cost	$ 3.9
Due in one to five years, Cost	43.3
Total Cost	47.2
Due in one year or less, Fair Value	3.9
Due in one to five years, Fair Value	43.6
Total Fair Value	$ 47.5

Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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Amount of available-for-sale debt securities at cost, net of adjustments, which include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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- Definition

Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the next fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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- Definition

Amount of debt securities categorized neither as held-to-maturity nor trading.

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