Stockholders' Equity (Dividend Restrictions) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified		0 Months Ended
Dec. 31, 2012	Aug. 17, 2012 Common Class A [Member]	Aug. 19, 2011 Common Class A [Member]	Aug. 17, 2012 Common Class B [Member]	Aug. 19, 2011 Common Class B [Member]
Class of Stock [Line Items]
Maximum dividend payment which may be paid without prior approval from Colorado Division of Insurance	$ 100.5
Common stock, dividends declared (in dollars per share)		$ 0.36	$ 0.36	$ 0.18	$ 0.18

The amount of dividends that may be paid or declared in any calendar year without prior approval of regulatory agencies.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(e))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph e

-Article 4

Name:	us-gaap_AmountAvailableForDividendDistributionWithoutPriorApprovalFromRegulatoryAgency
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant