Statutory Accounting and Regulatory Requirements (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statutory Accounting and Regulatory Requirements (Textual) [Abstract]
Dividends to the Company	10.00%
Dividends paid	$ 21.0	$ 32.0	$ 32.3
Dividends paid without seeking regulatory approval	$ 32.4

Amount available as of the balance sheet date for dividend payments after computation of statutory restrictions on capital surplus.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 60

-Paragraph 60

-Subparagraph h

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 505

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6486098&loc=d3e24708-158529

Name:	us-gaap_StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPayments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant