Stockholders’ Equity (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			12 Months Ended
	Aug. 31, 2018	Apr. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	May 31, 2018	Oct. 31, 2017
Class of Stock [Line Items]
Preferred shares, par value				$ 0.0001	$ 0.0001
Common Stock A [Member]
Class of Stock [Line Items]
Authorized number of shares for issuance in offering program							2,000,000
Issuance of common stock				100,000
Proceeds from issuance of stock, gross				$ 2.8
Payments of sales commissions				$ 0.1
Remaining number of shares for issuance in offering program				1,000,000
Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred shares issued		170,900	1,600,000	2,199,610	0
Preferred shares dividend rate			8.50%	8.50%	8.50%
Preferred shares, par value			$ 0.0001
Preferred shares, liquidation preference			25.00
Preferred shares, redemption price			$ 25.00
Net proceeds from issuance of preferred shares		$ 4.1	$ 38.3	$ 10.5
Payments of underwriting discount		$ 0.1
Authorized number of shares for issuance in offering program						2,200,000
Issuance of common stock				428,710
Payments of sales commissions				$ 0.2
Remaining number of shares for issuance in offering program				1,800,000
Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred shares issued	1,700,000			1,955,000	0
Preferred shares dividend rate	8.50%			8.50%	8.50%
Preferred shares, par value	$ 0.0001
Preferred shares, liquidation preference	$ 25.00
Preferred shares, redemption price				$ 25.00
Net proceeds from issuance of preferred shares	$ 41.2
Preferred shares issued, additional offering	255,000
Net proceeds from issuance of preferred shares, additional offering	$ 6.2
Payments of underwriting discount	$ 0.2
LIBOR [Member] | Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred shares, variable dividend rate			5.82%
LIBOR [Member] | Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred shares, variable dividend rate				5.69%