Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Preferred shares, par value (in dollars per share)	$ 0	$ 0
Preferred shares, authorized (in shares)	50,000,000	50,000,000
Preferred shares, issued (in shares)	9,042	9,042
Preferred shares, outstanding (in shares)	9,042	9,042
Preferred shares, liquidation preference	$ 94,096	$ 93,627
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	550,000,000	550,000,000
Common stock, shares issued (in shares)	173,712,510	171,656,039
Common stock, shares outstanding (in shares)	170,592,246	169,556,403
Treasury shares (in shares)	3,120,264	2,099,636