Earnings per share (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]

As of December 31, 2017, December 31, 2016, and December 31, 2015 the Company’s outstanding warrants and unvested restricted stock units were as follows:

	December 31, 2017		December 31, 2016		December 31, 2015
Outstanding warrants		1,007,500		1,007,500		1,007,500
Unvested restricted stock units previously granted to the Manager		60,000		20,003		40,006

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following table presents a reconciliation of the earnings and shares used in calculating basic and diluted EPS for the years ended December 31, 2017, 2016 and 2015:

	Year Ended		Year Ended		Year Ended
	December 31, 2017		December 31, 2016		December 31, 2015
Numerator:
Net income/(loss) available to common stockholders for basic and diluted earnings per share	$	105,088,194	$	50,213,355	$	349,121

Denominator:
Basic weighted average common shares outstanding		27,866,299		27,952,185		28,398,718
Dilutive effect of restricted stock units		16,822		926		11,190
Dilutive weighted average common shares outstanding		27,883,121		27,953,111		28,409,908

Basic Earnings/(Loss) Per Share of Common Stock:	$	3.77	$	1.80	$	0.01
Diluted Earnings/(Loss) Per Share of Common Stock:	$	3.77	$	1.80	$	0.01

Common Stock [Member]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following tables detail our common stock dividends during the years ended December 31, 2017, 2016 and 2015:

2017
Declaration Date	Record Date	Payment Date	Dividend Per Share
3/10/2017	3/21/2017	4/28/2017	$	0.475
6/8/2017	6/19/2017	7/31/2017		0.475
9/11/2017	9/29/2017	10/31/2017		0.575	*
12/15/2017	12/29/2017	1/31/2018		0.475

*The combined dividend of $0.575 includes a dividend of $0.475 per common share and a special cash dividend of $0.10 per common share.

2016
Declaration Date	Record Date	Payment Date	Dividend Per Share
3/10/2016	3/21/2016	4/29/2016	$	0.475
6/9/2016	6/20/2016	7/29/2016		0.475
9/12/2016	9/23/2016	10/31/2016		0.475
12/6/2016	12/19/2016	1/31/2017		0.475

2015
Declaration Date	Record Date	Payment Date	Dividend Per Share
3/12/2015	3/23/2015	4/30/2015	$	0.60
6/11/2015	6/22/2015	7/31/2015		0.60
9/10/2015	9/21/2015	10/30/2015		0.60
12/10/2015	12/21/2015	1/29/2016		0.475

Preferred Stock [Member]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following tables detail our preferred stock dividends during the years ended December 31, 2017, 2016 and 2015:

2017
Dividend	Declaration Date	Record Date	Payment Date	Dividend Per Share
8.25% Series A	2/16/2017	2/28/2017	3/17/2017	$	0.51563
8.25% Series A	5/15/2017	5/31/2017	6/19/2017		0.51563
8.25% Series A	8/16/2017	8/31/2017	9/18/2017		0.51563
8.25% Series A	11/16/2017	11/30/2017	12/18/2017		0.51563

Dividend	Declaration Date	Record Date	Payment Date	Dividend Per Share
8.00% Series B	2/16/2017	2/28/2017	3/17/2017	$	0.50
8.00% Series B	5/15/2017	5/31/2017	6/19/2017		0.50
8.00% Series B	8/16/2017	8/31/2017	9/18/2017		0.50
8.00% Series B	11/16/2017	11/30/2017	12/18/2017		0.50

2016
Dividend	Declaration Date	Record Date	Payment Date	Dividend Per Share
8.25% Series A	2/12/2016	2/29/2016	3/17/2016	$	0.51563
8.25% Series A	5/13/2016	5/31/2016	6/17/2016		0.51563
8.25% Series A	8/15/2016	8/31/2016	9/19/2016		0.51563
8.25% Series A	11/16/2016	11/30/2016	12/19/2016		0.51563

Dividend	Declaration Date	Record Date	Payment Date	Dividend Per Share
8.00% Series B	2/12/2016	2/29/2016	3/17/2016	$	0.50
8.00% Series B	5/13/2016	5/31/2016	6/17/2016		0.50
8.00% Series B	8/15/2016	8/31/2016	9/19/2016		0.50
8.00% Series B	11/16/2016	11/30/2016	12/19/2016		0.50

2015
Dividend	Declaration Date	Record Date	Payment Date	Dividend Per Share
8.25% Series A	2/12/2015	2/27/2015	3/17/2015	$	0.51563
8.25% Series A	5/14/2015	5/29/2015	6/17/2015		0.51563
8.25% Series A	8/14/2015	8/31/2015	9/17/2015		0.51563
8.25% Series A	11/13/2015	11/30/2015	12/17/2015		0.51563

Dividend	Declaration Date	Record Date	Payment Date	Dividend Per Share
8.00% Series B	2/12/2015	2/27/2015	3/17/2015	$	0.50
8.00% Series B	5/14/2015	5/29/2015	6/17/2015		0.50
8.00% Series B	8/14/2015	8/31/2015	9/17/2015		0.50
8.00% Series B	11/13/2015	11/30/2015	12/17/2015		0.50

- Definition

Tabular disclosure of warrants or rights issued. Warrants and rights outstanding are derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. The main difference between warrants and call options is that warrants are issued and guaranteed by the company, whereas options are exchange instruments and are not issued by the company. Also, the lifetime of a warrant is often measured in years, while the lifetime of a typical option is measured in months. Disclose the title of issue of securities called for by warrants and rights outstanding, the aggregate amount of securities called for by warrants and rights outstanding, the date from which the warrants or rights are exercisable, and the price at which the warrant or right is exercisable.

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