Note 6 - Stockholders' Equity - Changes in Equity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Balance	$ 1,870	$ 1,880	$ 1,834	$ 1,968
Net income	57	(174)	129	(114)
Other comprehensive income (loss)	28	25	8	(105)
Common stock dividends	(15)		(29)	(15)
Distributions to noncontrolling interests	(2)	(7)	(2)	(8)
Sale of noncontrolling interests	(1)		(1)
Redeemable noncontrolling interests adjustment to redemption value	(4)		(8)
Other	1		1
Stock compensation	5	(2)	12	3
Purchase of noncontrolling interests		(2)		(2)
Stock withheld for employee taxes			(5)	(6)
Balance	1,939	1,720	1,939	1,720
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance				(1)
Common Stock [Member]
Balance	2	2	2	2
Balance	2	2	2	2
Additional Paid-in Capital [Member]
Balance	2,415	2,391	2,408	2,386
Stock compensation	5	(2)	12	3
Purchase of noncontrolling interests		1		1
Balance	2,420	2,390	2,420	2,390
Retained Earnings [Member]
Balance	583	664	530	622
Net income	53	(174)	124	(116)
Common stock dividends	(15)		(29)	(15)
Redeemable noncontrolling interests adjustment to redemption value	(4)		(8)
Balance	617	490	617	490
Treasury Stock [Member]
Balance	(161)	(156)	(156)	(150)
Stock withheld for employee taxes			(5)	(6)
Balance	(161)	(156)	(161)	(156)
AOCI Attributable to Parent [Member]
Balance	(1,044)	(1,098)	(1,026)	(987)
Other comprehensive income (loss)	37	16	19	(95)
Balance	(1,007)	(1,082)	(1,007)	(1,082)
Noncontrolling Interest [Member]
Balance	75	77	76	95
Net income	4	0	5	2
Other comprehensive income (loss)	(9)	9	(11)	(10)
Distributions to noncontrolling interests	(2)	(7)	(2)	(8)
Sale of noncontrolling interests	(1)		(1)
Other	1		1
Purchase of noncontrolling interests		(3)		(3)
Balance	$ 68	$ 76	$ 68	$ 76