Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Basic Earnings per Common Share
Net income attributable to Company	$ 33,973	$ 27,845	$ 93,285	$ 61,364
Less: Preferred stock dividends	(5,925)	(3,225)	(17,775)	(9,675)
NET INCOME ATTRIBUTABLE TO COMPANY'S COMMON STOCKHOLDERS	$ 28,048	$ 24,620	$ 75,510	$ 51,689
Weighted average common shares outstanding-basic (in shares)	132,413	111,886	119,955	111,824
Basic Earnings per Common Share (in dollars per share)	$ 0.21	$ 0.22	$ 0.63	$ 0.46
Diluted Earnings per Common Share:
Net income attributable to Company	$ 33,973	$ 27,845	$ 93,285	$ 61,364
Less: Preferred stock dividends	(5,925)	(3,225)	(17,775)	(9,675)
Add back: Interest expense on convertible notes for the period, net of tax	2,570	2,428	7,838	6,982
Net income attributable to Company's common stockholders	$ 30,618	$ 27,048	$ 83,348	$ 58,671
Weighted average common shares outstanding-basic (in shares)	132,413	111,886	119,955	111,824
Net effect of assumed PSUs vested (in shares)	620	0	395	0
Net effect of assumed convertible notes conversion to common shares (in shares)	19,694	19,694	19,694	18,107
Diluted weighted average common shares outstanding (in shares)	152,727	131,580	140,044	129,931
Diluted Earnings per Common Share (in dollars per share)	$ 0.20	$ 0.21	$ 0.60	$ 0.45