Summary of Investments (Details 4) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Activity in the allowance for commercial mortgage loans credit losses
Beginning balance	$ 2,890	$ 2,890
Provision increases	0	273
Charge-off	0	(273)
Ending balance	2,890	2,890
Allowance ending balance by basis of impairment method:
Collectively evaluated for impairment	2,890	2,890
Mortgage Loans on Real Estate
Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:
Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:	3,178,573	3,137,145
Individually evaluated for impairment	13,082	13,906
Collectively evaluated for impairment	3,165,491	3,123,239
Mortgage Loans on Real Estate | Performing Financing Receivable
Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:
Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:	$ 3,178,573	$ 3,137,145