Fair Value Measurements (Quantitative Information About Level 3 Fair Value Measurements) (Details) (USD $)					9 Months Ended							9 Months Ended						9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Monte Carlo Simulation Approach [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Monte Carlo Simulation Approach [Member] Health Net Health Care Expenditures [Member] Minimum [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Monte Carlo Simulation Approach [Member] Health Net Health Care Expenditures [Member] Maximum [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Monte Carlo Simulation Approach [Member] Health Net Health Care Expenditures [Member] Weighted Average [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Monte Carlo Simulation Approach [Member] National Health Care Expenditures [Member] Minimum [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Monte Carlo Simulation Approach [Member] National Health Care Expenditures [Member] Maximum [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Monte Carlo Simulation Approach [Member] National Health Care Expenditures [Member] Weighted Average [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Income Approach [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Income Approach [Member] Minimum [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Income Approach [Member] Maximum [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Income Approach [Member] Weighted Average [Member]	Sep. 30, 2012 Western Region Operations [Member]	Dec. 31, 2011 Western Region Operations [Member]	Sep. 30, 2012 Western Region Operations [Member] Fair Value, Inputs, Level 3 [Member] Income Approach [Member]	Sep. 30, 2012 Western Region Operations [Member] Fair Value, Inputs, Level 3 [Member] Income Approach [Member] Minimum [Member]	Sep. 30, 2012 Western Region Operations [Member] Fair Value, Inputs, Level 3 [Member] Income Approach [Member] Maximum [Member]	Sep. 30, 2012 Western Region Operations [Member] Fair Value, Inputs, Level 3 [Member] Income Approach [Member] Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Embedded contractual derivative				$ 7,200,000
Goodwill	565,886,000	605,886,000													565,900,000	605,900,000	565,900,000
Deferred revenue related to transition-related services provided in connection with Medicare PDP business sale			4,000,000								4,000,000
Health Care Expenditures, range (as a percentage)					(2.20%)	13.00%	2.20%	(1.60%)	7.90%	3.10%
Discount Rate, range (as a percentage)												1.20%	1.20%	1.20%				9.00%	9.00%	9.00%
Costs estimated in connection with providing transition related services												$ 4,900,000	$ 4,900,000	$ 4,900,000