SCHEDULE I SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	$ 13,000
Estimated fair value	14,669
Amount at which shown in the balance sheet	14,669
Indemnity
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	669
Estimated fair value	703
Amount at which shown in the balance sheet	703
Indemnity | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	579
Estimated fair value	589
Amount at which shown in the balance sheet	589
Indemnity | States & political subdivisions | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	219
Estimated fair value	231
Amount at which shown in the balance sheet	231
Indemnity | Corporate debt securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	236
Estimated fair value	234
Amount at which shown in the balance sheet	234
Indemnity | Residential mortgage-backed securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	8
Estimated fair value	8
Amount at which shown in the balance sheet	8
Indemnity | Commercial mortgage-backed securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	52
Estimated fair value	51
Amount at which shown in the balance sheet	51
Indemnity | Collateralized debt obligations | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	33
Estimated fair value	33
Amount at which shown in the balance sheet	33
Indemnity | Other debt securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	7
Estimated fair value	7
Amount at which shown in the balance sheet	7
Indemnity | Total fixed maturities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	555
Estimated fair value	564
Amount at which shown in the balance sheet	564
Indemnity | Nonredeemable preferred stock | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	11
Estimated fair value	12
Amount at which shown in the balance sheet	12
Indemnity | Common stock | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	13
Estimated fair value	13
Amount at which shown in the balance sheet	13
Indemnity | Limited partnerships
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	89
Estimated fair value	113
Amount at which shown in the balance sheet	113
Indemnity | Real estate mortgage loans
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	1
Estimated fair value	1
Amount at which shown in the balance sheet	1
Exchange
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	12,331
Estimated fair value	13,966
Amount at which shown in the balance sheet	13,966
Exchange | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	9,328
Estimated fair value	9,857
Amount at which shown in the balance sheet	9,857
Exchange | Trading securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	2,289
Estimated fair value	3,223
Amount at which shown in the balance sheet	3,223
Exchange | U.S. treasury | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	6
Estimated fair value	6
Amount at which shown in the balance sheet	6
Exchange | Government sponsored enterprises | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	3
Estimated fair value	4
Amount at which shown in the balance sheet	4
Exchange | States & political subdivisions | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	1,394
Estimated fair value	1,477
Amount at which shown in the balance sheet	1,477
Exchange | Foreign government securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	10
Estimated fair value	10
Amount at which shown in the balance sheet	10
Exchange | Corporate debt securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	6,918
Estimated fair value	7,289
Amount at which shown in the balance sheet	7,289
Exchange | Residential mortgage-backed securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	109
Estimated fair value	111
Amount at which shown in the balance sheet	111
Exchange | Commercial mortgage-backed securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	28
Estimated fair value	30
Amount at which shown in the balance sheet	30
Exchange | Collateralized debt obligations | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	6
Estimated fair value	11
Amount at which shown in the balance sheet	11
Exchange | Other debt securities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	66
Estimated fair value	69
Amount at which shown in the balance sheet	69
Exchange | Total fixed maturities | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	8,540
Estimated fair value	9,007
Amount at which shown in the balance sheet	9,007
Exchange | Nonredeemable preferred stock | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	650
Estimated fair value	710
Amount at which shown in the balance sheet	710
Exchange | Common stock | Available-for-sale securities
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	138
Estimated fair value	140
Amount at which shown in the balance sheet	140
Exchange | Limited partnerships
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	694
Estimated fair value	866
Amount at which shown in the balance sheet	866
Exchange | Life policy loans
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	18
Estimated fair value	18
Amount at which shown in the balance sheet	18
Exchange | Real estate mortgage loans
SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
Amortized cost	2
Estimated fair value	2
Amount at which shown in the balance sheet	$ 2