Income Taxes (Details - Deferred Taxes and Valuation Allowance) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net operating losses	$ 782	$ 632
Reserves and allowances, net	482	601
Mark to market	158	110
Deferred compensation	44	43
Tax credits	44	37
Basis differences in investments	10	9
Other	28	1
Total deferred tax assets	1,548	1,433
Valuation allowance	(82)	(91)
Total deferred tax assets, net of valuation allowance	1,466	1,342
Deferred tax liabilities:
Depreciation and amortization	(433)	(387)
Other	0	(4)
Total deferred tax liabilities	(433)	(391)
Net deferred tax asset	1,033	951
Deferred Assets And Valuation Allowance (Texutals) [Line Items]
Valuation allowance	$ (82)	(91)
Period Trading and Investing Segment Generated Income	12 years
Increase (decrease) in valuation allowance	$ (9)
Total deferred tax assets	1,548	$ 1,433
Foreign Country [Member]
Deferred tax assets:
Total deferred tax assets	17
Valuation allowance	(17)
Deferred Assets And Valuation Allowance (Texutals) [Line Items]
Valuation allowance	(17)
Operating loss carryforwards	67
Other temporary differences	16
Total deferred tax assets	17
State and Local Jurisdiction [Member]
Deferred tax assets:
Total deferred tax assets	177
Valuation allowance	(65)
Deferred Assets And Valuation Allowance (Texutals) [Line Items]
Valuation allowance	(65)
Operating loss carryforwards	3,600
Total deferred tax assets	$ 177
State and Local Jurisdiction [Member] | Earliest Tax Year [Member]
Deferred Assets And Valuation Allowance (Texutals) [Line Items]
Operating loss carryforwards, expiration dates	Jan. 01, 2016
State and Local Jurisdiction [Member] | Latest Tax Year [Member]
Deferred Assets And Valuation Allowance (Texutals) [Line Items]
Operating loss carryforwards, expiration dates	Dec. 31, 2034
Federal Jurisdiction [Member]
Deferred tax assets:
Valuation allowance	$ 0
Deferred Assets And Valuation Allowance (Texutals) [Line Items]
Valuation allowance	0
Operating loss carryforwards	$ 1,800
Operating loss carryforwards, expiration period	12 years