Income Taxes - Components of the deferred tax assets and liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred assets
Unearned premium reserves	$ 545	$ 819
Accrued compensation	137	203
Pension	86	294
Discount on loss reserves	53	188
Net operating loss carryover	50	15
Other assets	49	103
Other postretirement benefits	48	64
Difference in tax bases of invested assets	0	78
Total deferred assets	968	1,764
Deferred liabilities
DAC	(770)	(1,211)
Unrealized net capital gains	(422)	(529)
Life and annuity reserves	(241)	(324)
Intangible assets	(113)	(29)
Difference in tax bases of invested assets	(106)	0
Other liabilities	(98)	(158)
Total deferred liabilities	(1,750)	(2,251)
Net deferred liability	$ (782)	$ (487)

The amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the tax basis of invested assets and the basis of invested assets computed in accordance with generally accepted accounting principles. The basic difference, whether due to impairment charges or other reasons, will decrease future taxable income when it reverses.

No definition available.