Condensed Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Investments:
Fixed maturities, available-for-sale, at fair value (amortized cost of $18,652.0 at 2013 and $18,458.7 at 2012)	$ 20,617.8	$ 20,690.8
Fixed maturities, at fair value using the fair value option	519.9	544.7
Equity securities, available-for-sale, at fair value (cost of $112.1 at 2013 and $129.3 at 2012)	127.0	142.8
Short-term investments	186.0	679.8
Mortgage loans on real estate, net of valuation allowance of $1.3 at 2013 and at 2012	3,060.7	2,872.7
Policy loans	237.6	240.9
Limited partnerships/corporations	182.0	179.6
Derivatives	479.1	512.7
Securities pledged (amortized cost of $302.4 at 2013 and $207.2 at 2012)	310.2	219.7
Total investments	25,720.3	26,083.7
Cash and cash equivalents	474.7	363.4
Short-term investments under securities loan agreement, including collateral delivered	294.5	186.1
Accrued investment income	292.8	273.0
Receivable for securities sold	29.4	3.9
Reinsurance recoverable	2,130.9	2,153.7
Deferred policy acquisition costs, Value of business acquired, and Sale inducements to contract owners	795.5	695.0
Notes receivable from affiliate	175.0	175.0
Due from affiliates	54.8	99.8
Property and equipment	81.1	81.8
Other assets	112.6	101.1
Assets held in separate accounts	57,650.3	53,655.3
Total assets	87,811.9	83,871.8
Liabilities and Shareholder's Equity
Future policy benefits and contract owner balances	24,207.3	24,191.2
Payable for securities purchased	21.9	0
Payables under securities loan agreement, including collateral held	436.4	353.2
Long-term debt	4.9	4.9
Due to affiliates	109.4	95.1
Derivatives	296.5	346.8
Current income tax payable to Parent	16.4	32.1
Deferred income taxes	464.5	507.1
Other liabilities	378.8	424.7
Liabilities related to separate accounts	57,650.3	53,655.3
Total liabilities	83,586.4	79,610.4
Shareholder's equity:
Common stock (100,000 shares authorized, 55,000 issued and outstanding; $50 per share value)	2.8	2.8
Additional paid-in capital	4,217.2	4,217.2
Accumulated other comprehensive income	912.0	1,023.0
Retained earnings (deficit)	(906.5)	(981.6)
Total shareholder's equity	4,225.5	4,261.4
Total liabilities and shareholder's equity	$ 87,811.9	$ 83,871.8