Equity and Earnings Per Common Share - Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Equity and Earnings Per Common Share
Net income	$ 9,648	$ 12,805
Less net income attributable to Series B Units		(413)
Less preferred stock dividends	(29)
Net income available to common shareholders	$ 9,619	$ 12,392
Net income per share–basic and diluted (in dollars per share)	$ 0.04	$ 0.07
Weighted average common shares outstanding–basic	253,877	186,188
Weighted average common shares outstanding–diluted	254,903	186,188