Guarantees and Contingent Liabilities (Details)								1 Months Ended			6 Months Ended	12 Months Ended	24 Months Ended
	May 16, 2017 plaintiff	Apr. 27, 2017 plaintiff	Jan. 27, 2017 appeal case	Nov. 22, 2016 plaintiff	Jul. 06, 2016 plaintiff	May 02, 2016 plaintiff	Jan. 01, 2015 plaintiff	Jun. 30, 2017 USD ($) trial plaintiff	Jun. 30, 2015 plaintiff defense	Dec. 31, 2007 claim	Jun. 30, 2017 USD ($) claim trial	Dec. 31, 2001 employee case	Jun. 30, 2017 USD ($) trial plaintiff defense	Dec. 31, 2016 USD ($)	Sep. 16, 2014 adjuster
Guarantees:
Limitations or indemnifications of reinsurance agreements								$ 0			$ 0		$ 0
Proceedings:
Number of class action cases										2	2	2
Loss contingency, number of plaintiffs	2	118	3	1	118	498	460	4	10			32	10
Number of defenses | defense									2				2
Loss contingency, number of trials | trial								2			2		2
Reserves for asbestos claims								$ 867,000,000			$ 867,000,000		$ 867,000,000	$ 912,000,000
Reinsurance recoverables for asbestos claims								419,000,000			419,000,000		419,000,000	444,000,000
Reserves for environmental claims								166,000,000			166,000,000		166,000,000	179,000,000
Reinsurance recoverables for environmental claims								36,000,000			36,000,000		36,000,000	$ 40,000,000
Minimum
Proceedings:
Loss contingencies, reasonably possible pretax loss exposure in excess of the amount accrued											0
Maximum
Proceedings:
Loss contingencies, reasonably possible pretax loss exposure in excess of the amount accrued											425,000,000
Residual guarantee
Guarantees:
Potential leased automobiles residual value								$ 40,000,000			$ 40,000,000		$ 40,000,000
Guarantee obligations term, low end of range											1 year
Guarantee obligations term, high end of range											4 years
Settled Litigation
Proceedings:
Loss contingency, number of plaintiffs | plaintiff								41
Pending Litigation
Proceedings:
Loss contingency, number of plaintiffs | plaintiff								8
Fair Labor Standards Act
Proceedings:
Loss contingency, pending claims, number | adjuster															105
New York Labor Law
Proceedings:
Loss contingency, pending claims, number | adjuster															137
Appeal Denied | Judicial Ruling
Proceedings:
Loss contingency, number of appeals | appeal			1
Appeal Granted | Judicial Ruling
Proceedings:
Loss contingency, number of appeals | appeal			2
Signed Releases Knowingly and Voluntarily
Proceedings:
Loss contingency, number of plaintiffs | plaintiff									2
Did Not Sign Releases Knowingly and Voluntarily
Proceedings:
Loss contingency, number of plaintiffs | plaintiff									8
Age Discrimination In Employment Act | Pending Litigation
Proceedings:
Loss contingency, number of plaintiffs | plaintiff								6