Contingencies and commitments (Tables)

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Minimum future rental commitments under non-cancelable operating leases

The following table summarizes the minimum future rental commitments under non-cancelable operating leases as of December 31, 2015 (in millions):

2016	$	127
2017	117
2018	107
2019	101
2020	98
Thereafter	199
Total minimum operating lease commitments	$	749