Note 13 - Employee Retirement Plans (Details) - Changes in Fair Value of Level 3 Assets for Defined Benefit Plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of plan assets at beginning of year	$ 3,263	$ 2,896
Fair value of plan assets at end of year	3,058	3,263
Private Equity Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of plan assets at beginning of year	192	207
Actual return on plan assets relating to assets still held at the reporting date	16	31
Transfers in and/or out of level 3	(45)	(46)
Fair value of plan assets at end of year	163	192
Real Estate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of plan assets at beginning of year	84	93
Actual return on plan assets relating to assets still held at the reporting date	12	8
Transfers in and/or out of level 3	(35)	(17)
Fair value of plan assets at end of year	61	84
Collateralized Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of plan assets at beginning of year	7	0
Transfers in and/or out of level 3	(5)	7
Fair value of plan assets at end of year	2	7
Insurance Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of plan assets at beginning of year	5	6
Actual return on plan assets relating to assets still held at the reporting date		1
Transfers in and/or out of level 3	(2)	(2)
Fair value of plan assets at end of year	$ 3	$ 5