Note 6 - Stockholders' Equity - Changes in Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Balance	$ 1,720	$ 1,814	$ 1,968	$ 1,442
Net income	49	114	(65)	150
Other comprehensive income	23	(38)	(82)	355
Distributions to noncontrolling interests	(2)	(2)	(10)	(14)
Purchase of noncontrolling interests	1
Stock compensation	2	5	5	13
Common stock dividends		(15)	(15)	(44)
Purchase of noncontrolling interests			(1)
Stock withheld for employee taxes			(6)	(6)
Increase from business combination				8
Common stock share repurchases				(25)
Balance	1,793	1,878	1,793	1,878
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Balance			(1)
Accounting Standards Update 2016-02 [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Balance				(1)
Common Stock [Member]
Balance	2	2	2	2
Balance	2	2	2	2
Additional Paid-in Capital [Member]
Balance	2,390	2,376	2,386	2,368
Purchase of noncontrolling interests
Stock compensation	2	5	5	13
Purchase of noncontrolling interests			1
Balance	2,392	2,381	2,392	2,381
Retained Earnings [Member]
Balance	490	456	622	456
Net income	45	111	(71)	141
Common stock dividends		(15)	(15)	(44)
Balance	535	552	535	552
Retained Earnings [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance			(1)
Retained Earnings [Member] | Accounting Standards Update 2016-02 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance				(1)
Treasury Stock [Member]
Balance	(156)	(150)	(150)	(119)
Stock withheld for employee taxes			(6)	(6)
Common stock share repurchases				(25)
Balance	(156)	(150)	(156)	(150)
AOCI Attributable to Parent [Member]
Balance	(1,082)	(968)	(987)	(1,362)
Other comprehensive income	12	(26)	(83)	368
Balance	(1,070)	(994)	(1,070)	(994)
Noncontrolling Interest [Member]
Balance	76	98	95	97
Net income	4	3	6	9
Other comprehensive income	11	(12)	1	(13)
Distributions to noncontrolling interests	(2)	(2)	(10)	(14)
Purchase of noncontrolling interests	1
Purchase of noncontrolling interests			(2)
Increase from business combination				8
Balance	$ 90	$ 87	$ 90	$ 87