Commitments and Contingencies (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases, Capital
Assets acquired through capital leases	$ 19	$ 10	$ 10
Depreciation expense	9	5	19
Cash payments towards capital leases	8	6	$ 20
Assets included in property, plant and equipment	57	40
Accumulated depreciation	24	$ 22
Capital lease obligations:
2018	14
2019	10
2020	6
2021	2
2022	1
2023 and thereafter	3
Total minimum payments	36
Less: amount representing interest and executory costs	(6)
Present value of minimum payments	30
Less: current portion	(12)
Long-term portion	$ 18