Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Schedule of debt instruments

Debt is composed of the following obligations.

December 31
(In millions)	2017		2016
Short term debt:
Senior notes of CNAF, 6.950%, face amount of $150, due January 15, 2018	$	150	$	—
Long term debt:
Senior notes of CNAF:
6.950%, face amount of $150, due January 15, 2018	—		150
7.350%, face amount of $350, due November 15, 2019	—		349
5.875%, face amount of $500, due August 15, 2020	498		498
5.750%, face amount of $400, due August 15, 2021	398		398
3.950%, face amount of $550, due May 15, 2024	547		546
4.500%, face amount of $500, due March 1, 2026	498		498
3.450%, face amount of $500, due August 15, 2027	495		—
Debenture of CNAF, 7.250%, face amount of $243, due November 15, 2023	242		241
Subordinated variable rate debt of Hardy, face amount of $30, due September 15, 2036	30		30
Total long term debt	2,708		2,710
Total debt	$	2,858	$	2,710

Maturity of debt

The combined aggregate maturities for debt as of December 31, 2017 are presented in the following table.

(In millions)
2018	$	150
2019	—
2020	500
2021	400
2022	—
Thereafter	1,823
Less discount	(15		)
Total	$	2,858