Note 5 - Earnings (Loss) Per Common Share (Details Textual) - $ / shares	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Common Stock, Shares Authorized	750,000,000	750,000,000		750,000,000
Common Stock, Par or Stated Value Per Share	$ 0.25	$ 0.25		$ 0.25
Common Stock, Shares, Issued, Total	401,322,377	401,322,377		399,176,425
Treasury Stock, Shares, Ending Balance	5,226,791	5,226,791		4,529,450
Common Stock, Shares, Outstanding, Ending Balance	401,322,377	401,322,377		399,176,425
Restricted Stock Units (RSUs) [Member]
Incremental Common Shares Attributable to Share-based Payment Arrangements, Total	1,268,601	1,179,086	2,109,789
Deferred Shares [Member]
Incremental Common Shares Attributable to Share-based Payment Arrangements, Total	1,721,932	1,721,932	1,352,470