Debt (Tables)

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Schedule of Debt [Table Text Block]

							Interest Rates
	Debt						Average Contractual				Average Effective
	December 31, 2017			March 31, 2018			2017		2018		2017		2018
Short-term debt
Unsecured debt
Floating rate demand notes	$	5,660		$	5,735
Commercial paper	4,889			4,758
Other short-term debt	5,890			5,034
Asset-backed debt	786			1,138
Total short-term debt	17,225			16,665			3.0	%	2.9	%	3.0	%	2.9	%
Long-term debt
Unsecured debt
Notes payable within one year	13,298			14,195
Notes payable after one year	55,687			56,504
Asset-backed debt (a)
Notes payable within one year	17,817			18,461
Notes payable after one year	34,051			36,744
Unamortized discount	(1		)	1
Unamortized issuance costs	(228		)	(236		)
Fair value adjustments (b)	(21		)	(360		)
Total long-term debt	120,603			125,309			2.5	%	2.6	%	2.6	%	2.6	%
Total debt	$	137,828		$	141,974		2.6	%	2.6	%	2.6	%	2.7	%
Fair value of debt (c)	$	139,677		$	142,952