Fair Value (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010
Fair Value [Abstract]
Auction rate securities that have failed at auction and are currently illiquid	$ 5.8
Basis points to set the interest rate of each of the auction rate securities	225
Realized loss related to an other-than-temporary impairment	8.7
Carrying value of securities	5.8
Unrealized loss		$ 1.4
Transfer of investments into or out of Levels 1, 2 and 3	not	not

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

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+ Details