Note 13 - Capital Stock - Share-based Compensation (Details)		6 Months Ended
		Jun. 30, 2020 anniversary $ / shares shares	Dec. 31, 2019 $ / shares shares
Performance Based RSUs Equity Settled
Number of Shares, Unvested | shares	[1]	2,224,408	2,448,347
Number of Shares, Granted | shares	[2]	1,175,062
Number of Shares, Performance adjustment | shares	[3]	(792,420)
Number of Shares, Vested in Period | shares	[4]	(591,118)
Number of Shares, Forfeited | shares		(15,463)
Weighted Average Grant Date Fair Value, Unvested | $ / shares	[1]	$ 14.44	$ 17.03
Weighted Average Grant Date Fair Value, Granted | $ / shares	[2]	12.02
Weighted Average Grant Date Fair Value, Performance Adjustment | $ / shares	[3]	0
Weighted Average Grant Date Fair Value, Vested | $ / shares	[4]	17.59
Weighted Average Grant Date Fair Value, Forfeited | $ / shares		$ 20.00
Performance Based RSUs Equity Settled | 2020 Award Year
Performance Period, Performance-based RSUs		3 years
Performance Based RSUs Equity Settled | 2020 Award Year | Maximum
Payout Percentage of Target Award		200.00%
Performance Based RSUs Equity Settled | 2020 Award Year | Minimum
Payout Percentage of Target Award		0.00%
Time Vested RSUs Equity Settled
Number of Shares, Unvested | shares	[1]	957,913	697,576
Number of Shares, Granted | shares	[2]	659,914
Number of Shares, Performance adjustment | shares	[3]	0
Number of Shares, Vested in Period | shares	[4]	(395,093)
Number of Shares, Forfeited | shares		(4,484)
Weighted Average Grant Date Fair Value, Unvested | $ / shares	[1]	$ 16.48	$ 19.72
Weighted Average Grant Date Fair Value, Granted | $ / shares	[2]	13.69
Weighted Average Grant Date Fair Value, Performance Adjustment | $ / shares	[3]	0
Weighted Average Grant Date Fair Value, Vested | $ / shares	[4]	17.45
Weighted Average Grant Date Fair Value, Forfeited | $ / shares		$ 22.87
Time Vested RSUs Equity Settled | 2020 Award Year
Number of Anniversaries of the Grant Date | anniversary		3
Time Vested RSUs Equity Settled | 2020 Award Year | Minimum
Cliff-Vesting Period		1 year

[1] The final number of RSUs distributed depends on the level of performance achieved along with each employee’s continued service through the vest date, which could result in changes in vested RSUs.

[2] For performance-based RSUs, amount represents the probable outcome at grant date.

[3] Represents an adjustment to the number of unvested performance-based RSUs due to changes during the period in our estimated payouts, which can range from 0 to 200% of target depending on results over the applicable performance periods.

[4] Represents amounts vested during the year, which can include both original shares granted and the impact of performance adjustments.