Stockholders' Equity (Share-Based Payments - General Descriptions) (Details) (USD $)	3 Months Ended						12 Months Ended										12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 Common Class A [Member]	Dec. 31, 2011 Common Class A [Member]	Jun. 20, 2008 Common Class A [Member]	Jun. 25, 2004 Common Class A [Member]	Jun. 25, 2004 Stock and Incentive Plan, 1995 Plan [Member]	Jun. 20, 2008 Stock and Incentive Plan, 2008 Plan [Member]	Dec. 31, 2012 Director [Member]	Dec. 31, 2012 Employees [Member]	Dec. 31, 2012 Colorado Division of Insurance [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Current authorized control level RBC																			$ 72,900,000
Adjusted Capital							1,004,766,000	922,522,000	878,451,000										1,100,000,000
Pre-tax compensation cost (benefit) recognized							1,100,000	(2,600,000)	(100,000)
Share-based payments, number of shares authorized under plans															300,000	300,000
Common stock, par value											$ 1	$ 1	$ 1.00	$ 1.00
Requisite service period of awards																	1 year	3 years
Expiration period of awards							10 years
Awards issued during the period (in shares)	0	0	0	0	0	0
Period in force, from which option holders may elect to sell back acquired shares							90 days
Compensation cost related to nonvested options not yet recognized, weighted-average period of recognition							2 years 3 months 18 days
Annual vesting percentage																	20.00%	20.00%
Compensation cost, liability balance							2,700,000	1,600,000
Compensation cost (benefit), tax expense (benefit)							400,000	(900,000)	0
Period of recognition							$ 1,700,000	$ 2,200,000		$ 1,800,000