Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Statement of Cash Flows [Abstract]
Net cash provided by operating activities	$ 792.4	$ 695.8
Proceeds from the sale, maturity, disposal or redemption of:
Fixed maturities	2,932.6	4,859.7
Equity securities, available-for-sale	2.4	78.8
Mortgage loans on real estate	303.5	258.6
Limited partnerships/corporations	136.6	63.1
Acquisition of:
Fixed maturities	(3,890.2)	(4,961.5)
Equity securities, available-for-sale	(0.7)	(55.5)
Mortgage loans on real estate	(642.5)	(721.7)
Limited partnerships/corporations	(28.2)	(48.6)
Derivatives, net	4.6	(38.8)
Policy loans, net	3.4	4.2
Short-term investments, net	(116.7)	(355.6)
Loan-Dutch State obligation, net	63.1	88.5
Collateral held, net	51.8	36.6
Sales (purchases) of fixed assets, net	(0.2)	(0.8)
Net cash provided by (used in) investing activities	(1,180.5)	(793.0)
Cash Flows from Financing Activities:
Deposits received for investment contracts	2,009.3	2,314.8
Maturities and withdrawals from investment contracts	(1,763.9)	(1,816.1)
Short-term loans to affiliates	(648.0)	343.1
Short-term repayments of repurchase agreements, net	0	(214.4)
Capital (distribution/dividends) contribution to/from parent	(340.0)	201.0
Net cash provided by (used in) financing activities	553.4	142.2
Net increase in cash and cash equivalents	165.3	45.0
Cash and cash equivalents, beginning of period	217.1	231.0
Cash and cash equivalents, end of period	$ 382.4	$ 276.0