Note 3 - Brookfield Investment (Details Textual) $ / shares in Units, $ in Thousands						3 Months Ended	12 Months Ended
	Feb. 27, 2019 USD ($) $ / shares shares	Feb. 27, 2018 USD ($) $ / shares shares	Jun. 30, 2017 $ / shares	Mar. 31, 2017 USD ($) $ / shares shares	Jan. 12, 2017 USD ($)	Mar. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) shares
Preferred Stock, Shares Outstanding, Ending Balance | shares				1		1	1	1
Preferred Stock, Par or Stated Value Per Share | $ / shares				$ 0.01		$ 0.01	$ 0.01	$ 0.01
Number Of Directors Eligible For Election By Investors							2
Number Of Additional Directors Eligible For Election By Investors							2
Number Of Directors With Approval Rights							1
Temporary Equity, Dividends, Adjustment							$ 46,286	$ 20,830	$ 13,103
Payments of Dividends, Total							27,990	12,694	8,221
Securities Purchase Voting and Standstill Agreement [Member]
Sale of Stock, Consideration Received on Transaction					$ 400,000
Class C Units [Member]
Temporary Equity, Dividends, Adjustment						$ 4,500
Cash Distributions, Percent Per Year	7.50%		7.50%
Cash Distributions, Percent Per Year, Potential Increased Rate			10.00%
Paid-in-kind Distributions, Percent Per Year	5.00%		5.00%
Paid-in-kind Distributions, Percent Per Year, Potential Increased Rate			7.50%
Paid-in-kind Distributions, Potential Additional Increase in Distribution Rate Per Quarter			1.25%
Paid-in-kind Distributions, Maximum Percent Per Year			12.50%
Paid-in-kind Distributions, Denominator for Distributions | $ / shares			$ 14.75
Temporary Equity, Tax Distributions							0
Payments of Dividends, Total							$ 27,800	$ 12,500	$ 7,900
Paid-in-kind Distributions, Number of Units | shares							1,255,214.93	564,870.56	355,349.6
Convertible Equity, Conversion Price | $ / shares							$ 14.75
Related Party Transaction, Minimum Amount of Assets for Transfers without Consent							$ 100,000
Related Party Transaction, Minimum Percent of Class C Units to Outstanding Common Stock to Trigger Preemptive Rights							5.00%
Class C Units [Member] | Brookfield Investor [Member[
Related Party Transaction, Expenses from Transactions with Related Party							$ 6,000
Class C Units [Member] | Securities Purchase Voting and Standstill Agreement [Member]
Sale of Stock, Number of Shares Issued in Transaction | shares	14,898,060.78	1,694,915.25		9,152,542.37		9,152,542.37
Sale of Stock, Price Per Share | $ / shares	$ 14.75	$ 14.75		$ 14.75		$ 14.75
Sale of Stock, Consideration Received on Transaction	$ 219,700	$ 25,000		$ 135,000