CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 692	$ 668
Accounts receivable	181	169
Inventories	388	380
Prepaid expenses and other current assets	66	76
Property, plant and equipment, net	2,356	2,430
Other long-term assets	279	277
Current liabilities:
Accounts payable	390	320
Other current liabilities	200	176
Long-term debt and finance lease obligations	1,190	1,167
Other long-term liabilities	$ 52	$ 14
Equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	350,000,000	350,000,000
Common stock, issued (in shares)	100,629,209	100,629,209
Treasury stock (in shares)	98,610	98,610
Variable Interest Entities
Current assets:
Cash and cash equivalents	$ 84	$ 415
Accounts receivable	15	169
Inventories	57	380
Prepaid expenses and other current assets	5	56
Property, plant and equipment, net	965	2,414
Other long-term assets	56	270
Current liabilities:
Accounts payable	32	317
Other current liabilities	53	154
Long-term debt and finance lease obligations	632	1,167
Other long-term liabilities	$ 12	$ 7