Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Stockholders' Equity
Unrealized gains on securities, tax	$ 0.9	$ 1.2	$ 0.5
Shares issued in connection with financing, financing costs			$ 8.1

Tax effect of the appreciation (loss) in the value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) losses.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e640-108580

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