Note 11 - Share-based Awards and Cash-based Awards - Summary of Share Activity Related to Restricted Stock Units (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Nonvested, units (in shares)	3,355,917	5,765,251	6,107,248
Nonvested, beginning of period (in dollars per share)	$ 3.90	$ 2.48	$ 2.73
Granted, units (in shares)	994,698	988,955	2,128,879
Granted, weighted average grant date fair value per unit (in dollars per share)	$ 4.51	$ 6.90	$ 2.76
Vested, units (in shares)	(1,475,373)	(2,261,665)	(2,108,553)
Vested (in dollars per share)	$ 2.76	$ 2.21	$ 3.45
Forfeited, units (in shares)	(1,260,520)	(1,136,624)	(362,323)
Forfeited, weighted average grant date fair value per unit (in dollars per share)	$ 3.37	$ 2.68	$ 2.87
Nonvested, units (in shares)	1,614,722	3,355,917	5,765,251
Nonvested, end of period (in dollars per share)	$ 5.73	$ 3.90	$ 2.48