Schedule I - Condensed Financial Information of Registrant (Condensed Statements of Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended														12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013		Jun. 30, 2013	Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Net income	$ 19,800	$ 66,800	[1]	$ 33,500	$ 50,100	[2]	$ 6,000	[3],[4]	$ 18,000	[5]	$ 124,600	[6]	$ (26,600)	[7]	$ 170,126	$ 122,063	$ 72,120
Unrealized (losses) gains on investments available-for-sale:
Unrealized holding (losses) gains arising during the period															(78,217)	65,462	54,607
Less: Reclassification adjustments for gains included in earnings															(23,975)	(36,680)	(33,029)
Unrealized gains on investments available-for-sale, net															(102,192)	28,782	21,578
Defined benefit pension plans:
Prior service cost arising during the period															607	0	(1,304)
Net gain (loss) arising during the period															7,294	(646)	(12,904)
Less: Amortization of prior service cost and net loss included in net periodic pension cost															2,572	4,152	628
Defined benefit pension plans, net															10,473	3,506	(13,580)
Other comprehensive (loss) income, before tax															(91,719)	32,288	7,998
Income tax (benefit) expense related to components of other comprehensive income															(31,868)	21,936	(8,147)
Other comprehensive income, net of tax															(59,851)	10,352	16,145
Comprehensive income															110,275	132,415	88,265
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net income															170,126	122,063	72,120
Unrealized (losses) gains on investments available-for-sale:
Unrealized holding (losses) gains arising during the period															(78,217)	65,462	54,607
Less: Reclassification adjustments for gains included in earnings															(23,975)	(36,680)	(33,029)
Unrealized gains on investments available-for-sale, net															(102,192)	28,782	21,578
Defined benefit pension plans:
Prior service cost arising during the period															607	0	(1,304)
Net gain (loss) arising during the period															7,294	(646)	(12,904)
Less: Amortization of prior service cost and net loss included in net periodic pension cost															2,572	4,152	628
Defined benefit pension plans, net															10,473	3,506	(13,580)
Other comprehensive (loss) income, before tax															(91,719)	32,288	7,998
Income tax (benefit) expense related to components of other comprehensive income															(31,868)	21,936	(8,147)
Other comprehensive income, net of tax															(59,851)	10,352	16,145
Comprehensive income															$ 110,275	$ 132,415	$ 88,265

[1] Includes $32.1 million of Medicaid premium revenue as a result of Medicaid/Medi-Cal retroactive rate adjustments for periods prior to 2013.

[2] Includes $42.2 million of Medicaid premium revenue as a result of Medicaid/Medi-Cal retroactive rate adjustments related to 2011 and 2012.

[3] Includes a $2.2 million unfavorable adjustment to the gain on sale of discontinued operation, an $8.2 million expense related to our G&A cost reduction efforts, a $5.0 million expense related to the early termination of a medical management contract and $7.1 million of litigation-related expenses.

[4] Includes $31.5 million of premium revenue as a result of Medicaid/Medi-Cal retroactive rate adjustment related to the third quarter of 2012 and prior periods.

[5] Includes a $2.4 million unfavorable adjustment to the gain on sale of discontinued operation and a $7.2 million expense related to our G&A cost reduction efforts.

[6] Includes $119.4 million gain on sale of discontinued operation related to the sale of our Medicare PDP business to CVS Caremark. Also includes $7.9 million of adverse development related to prior years recorded as part of health care costs, and a $10.8 million expense related to our G&A cost reduction efforts.

[7] Includes $25.0 million of adverse development related to prior periods recorded as part of health care costs, a $9.5 million expense related to our G&A cost reduction efforts and an unfavorable $0.7 million in pretax litigation reserve adjustment. Also includes a $6.5 million insurance reimbursement related to a prior legal settlement.