Note 14 - Capital Stock - Share Repurchase Activity (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended
	Jul. 31, 2021	Jun. 30, 2021	Jun. 30, 2021	Feb. 13, 2020	Aug. 14, 2019
3Q19 Repurchase Program
Capital Stock [Line Items]
Stock Repurchase Program, Authorized Amount					$ 200.0
1Q20 Repurchase Program
Capital Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 275.0
Total of 3Q19 and 1Q20 Repurchase Programs
Capital Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 475.0
Stock Repurchased During Period, Shares		3,892,456	4,305,597
Accelerated Share Repurchases, Final Price Paid Per Share		$ 23.14	$ 22.92
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 100.2	$ 100.2
Total of 3Q19 and 1Q20 Repurchase Programs | Subsequent Event
Capital Stock [Line Items]
Stock Repurchased During Period, Shares	2,808,658
Accelerated Share Repurchases, Final Price Paid Per Share	$ 21.86
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 38.9