Note 1 - Organization and Summary of Significant Accounting Policies - Effect of Error Correction on Financial Statements (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Net income (loss)	$ 45	$ 38	$ 112	$ (90)	$ 147
Less: Noncontrolling interests net income	4	2	3	6	9
Less: Redeemable noncontrolling interests net loss	(4)	(22)	(2)	(25)	(3)
Net income attributable to the parent company	$ 45	$ 58	$ 111	$ (71)	$ 141
Basic (in dollars per share)	$ 0.31	$ 0.40	$ 0.77	$ (0.49)	$ 0.98
Diluted (in dollars per share)	$ 0.31	$ 0.40	$ 0.77	$ (0.49)	$ 0.97
Total comprehensive loss	$ 64	$ (84)	$ 79	$ (172)	$ 511
Less: Comprehensive (income) loss attributable to noncontrolling interests	(15)	17	9	(7)	4
Less: Comprehensive (income) loss attributable to redeemable noncontrolling interests	8	14	(3)	25	(6)
Comprehensive income (loss) attributable to the parent company	57	(53)	$ 85	(154)	$ 509
Redeemable noncontrolling interests	152	155		152		$ 167
Retained earnings	$ 535	664		$ 535		$ 622
Previously Reported [Member]
Net income (loss)		38
Less: Noncontrolling interests net income		2
Less: Redeemable noncontrolling interests net loss		(2)
Net income attributable to the parent company		$ 38
Basic (in dollars per share)		$ 0.26
Diluted (in dollars per share)		$ 0.26
Total comprehensive loss		$ (84)
Less: Comprehensive (income) loss attributable to noncontrolling interests		17
Less: Comprehensive (income) loss attributable to redeemable noncontrolling interests		(6)
Comprehensive income (loss) attributable to the parent company		(73)
Redeemable noncontrolling interests		175
Retained earnings		644
Revision of Prior Period, Adjustment [Member]
Net income (loss)		0
Less: Noncontrolling interests net income
Less: Redeemable noncontrolling interests net loss		(20)
Net income attributable to the parent company		$ 20
Basic (in dollars per share)		$ 0.14
Diluted (in dollars per share)		$ 0.14
Total comprehensive loss		$ 0
Less: Comprehensive (income) loss attributable to noncontrolling interests
Less: Comprehensive (income) loss attributable to redeemable noncontrolling interests		20
Comprehensive income (loss) attributable to the parent company		20
Redeemable noncontrolling interests		(20)
Retained earnings		$ 20