Investments (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Investment [Line Items]
Net change in unrealized gains (losses) from trading account assets supporting insurance liabilities	$ (2,800,000)	$ (1,100,000)	$ (2,200,000)	$ (400,000)
% of Total			100.00%		100.00%
Impaired Financing Receivable, Related Allowance	800,000		$ 800,000		$ 900,000
Impaired Financing Receivable Interest Income Recognized	600,000		600,000		800,000
Amortization Method Qualified Affordable Housing Project Investments	600,000		600,000		800,000
Qualified Affordable Housing Project Investments, Commitment (less than)	100,000		100,000		100,000
Gain (loss) from Affordable Housing Projects, Equity Method Investments (less than for three month periods)	100,000	100,000	100,000	100,000
Affordable Housing Tax Credits And Other Tax Benefits, Amount	100,000	$ 100,000	200,000	$ 200,000
Affordable Housing Project Investment, Write-down, Amount			0
Investment Grade Securities Gross Unrealized Losses	89,900,000		89,900,000		21,300,000
Gross unrealized losses related to other than high or highest quality securities	16,500,000		16,500,000		6,300,000
Available For Sale Securities Continuous Unrealized Loss Twelve Months Or Longer	24,600,000		24,600,000		12,000,000
Securities Loaned, Including Not Subject To Master Netting Arrangement And Assets Other Than Securities Transferred	69,000,000		69,000,000
Maturity Overnight
Investment [Line Items]
Securities Loaned, Including Not Subject To Master Netting Arrangement And Assets Other Than Securities Transferred	68,000,000		68,000,000
Maturity Less than 30 Days
Investment [Line Items]
Securities Loaned, Including Not Subject To Master Netting Arrangement And Assets Other Than Securities Transferred	1,000,000		1,000,000
Equity securities
Investment [Line Items]
Gross unrealized losses representing declines in value of greater than 20% (less than in 2015)	100,000		100,000		0
Commercial Loan on Other
Investment [Line Items]
Financing Receivable, Recorded Investment, Past Due	0		0		0
All other corporate securities
Investment [Line Items]
Securities Loaned, Including Not Subject To Master Netting Arrangement And Assets Other Than Securities Transferred	57,000,000		57,000,000
Foreign government bonds
Investment [Line Items]
Securities Loaned, Including Not Subject To Master Netting Arrangement And Assets Other Than Securities Transferred	7,000,000		7,000,000
U.S. Treasury securities and obligations of U.S. government authorities and agencies
Investment [Line Items]
Securities Loaned, Including Not Subject To Master Netting Arrangement And Assets Other Than Securities Transferred	5,000,000		5,000,000
Commercial Loan
Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,700,000,000		1,700,000,000		1,700,000,000
Commercial Loan on Hospitality
Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 15,900,000		$ 15,900,000		$ 15,900,000
California
Investment [Line Items]
% of Total			23.00%
Texas
Investment [Line Items]
% of Total			11.00%
New Jersey
Investment [Line Items]
% of Total			9.00%