Goodwill and other intangible assets (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization charges associated with finite-lived intangible assets	$ 318	$ 331	$ 948	$ 983
Total estimated amortization of finite-lived intangible assets for the three months ending December 31, 2019	300		300
Total estimated amortization of finite-lived intangible assets for 2020	1,200		1,200
Total estimated amortization of finite-lived intangible assets for 2021	1,000		1,000
Total estimated amortization of finite-lived intangible assets for 2022	900		900
Total estimated amortization of finite-lived intangible assets for 2023	900		900
Total estimated amortization of finite-lived intangible assets for 2024	$ 900		$ 900