Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 1,606	$ 2,329
Accounts receivable, net	1,184	1,198
Materials and supplies	845	829
Current portion of deferred income taxes	0	245
Other current assets	382	337
Total current assets	4,017	4,938
Property and equipment, net of accumulated depreciation of $5,135 and $4,845, respectively	59,900	59,510
Goodwill	14,845	14,845
Intangible assets, net	458	468
Other assets	1,971	1,942
Total assets	81,191	81,703
Current liabilities:
Accounts payable and other current liabilities	3,035	3,244
Long-term debt due within one year	203	389
Total current liabilities	3,238	3,633
Long-term debt	21,315	21,348
Deferred income taxes	19,018	19,072
Intangible liabilities, net	642	667
Casualty and environmental liabilities	598	609
Pension and retiree health and welfare liability	352	353
Other liabilities	964	989
Total liabilities	$ 46,127	$ 46,671
Commitments and contingencies (see Notes 6 and 7)
Equity:
Member's equity	$ 35,018	$ 34,984
Accumulated other comprehensive loss	46	48
Total equity	35,064	35,032
Total liabilities and equity	$ 81,191	$ 81,703