CONDENSED CONSOLIDATED STATEMENT OF EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock Series A Preferred Stock	Preferred Stock Series B Preferred Stock	Preferred Stock Series C Preferred Stock	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Distributions in excess of earnings)	Total Stockholders’ Equity	Non- Controlling Interest
Balance at beginning of period at Dec. 31, 2016							$ 293,668
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 94,032
Other comprehensive income (loss)	10,226
Balance at end of period at Mar. 31, 2017							303,765
Beginning Balance (in shares) at Dec. 31, 2017		5,600,000	6,200,000	11,500,000	111,624,159
Balance at beginning of period at Dec. 31, 2017	2,656,878	$ 135,356	$ 149,860	$ 278,108	$ 1,116	$ 2,384,356	261,029	$ (579,334)	$ 2,630,491	$ 26,387
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	53,249							52,578	52,578	671
Other comprehensive income (loss)	(129,307)						(127,677)		(127,677)	(1,630)
Stock awards (in shares)					12,564
Common stock dividends	(46,887)							(46,887)	(46,887)
Common unit dividends	(599)									(599)
Preferred stock dividends	(11,107)							(11,107)	(11,107)
Amortization of equity-based compensation	129					127			127	2
Rebalancing of ownership percentage of non-controlling interest						143	0		143	(143)
Ending Balance (in shares) at Mar. 31, 2018		5,600,000	6,200,000	11,500,000	111,636,723
Balance at end of period at Mar. 31, 2018	$ 2,522,356	$ 135,356	$ 149,860	$ 278,108	$ 1,116	$ 2,384,626	$ 133,352	$ (584,750)	$ 2,497,668	$ 24,688