Stockholders' Equity - Additional Information (Details) - USD ($)										3 Months Ended		91 Months Ended
	Feb. 17, 2022	Feb. 18, 2021	May 11, 2020	Mar. 13, 2020	Mar. 04, 2020	Feb. 20, 2020	Feb. 21, 2019	Apr. 30, 2018	Jun. 15, 2016	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock, shares, issued										25,700,190		25,700,190	25,500,567
Common stock, shares, outstanding										25,700,190		25,700,190	25,500,567
Common stock, par value										$ 0.01		$ 0.01	$ 0.01
Share repurchase program, authorized amount				$ 100,000.0				$ 40,000.0	$ 30,000,000.0
Stock repurchase program period in force								2 years	2 years
Stock repurchase program, expiration date				Mar. 12, 2023				Jun. 15, 2020	Jun. 15, 2018
Share repurchase program, treasury stock shares										0	0	2,382,155
Share repurchase program, treasury stock, value												$ 61,200,000
Share repurchase program, treasury stock, per share												$ 25.70
Common stock, shares, retired										0	0
Treasury stock, shares										0	0	0
Shares issued average price per share					$ 53.70
Proceeds from issuance of common stock					$ 62,310,967,000					$ 4,138,000	$ (176,000)
Common Stock
Class Of Stock [Line Items]
Common stock, shares, issued										25,700,190	25,127,141	25,700,190	25,500,567	25,016,957
Restricted Stock Units
Class Of Stock [Line Items]
Restricted stock units, granted										142,159
At-the-Market Offering
Class Of Stock [Line Items]
Shares, issued										52,091
2020 At-the-Market Offering
Class Of Stock [Line Items]
Shares, issued										52,091
Shares issued average price per share										$ 83.16
Proceeds from issuance of common stock										$ 4,300,000
Stock issuance costs										100,000
Stock Issuance Costs Other										$ 100,000
2020 At-the-Market Offering | Common Stock
Class Of Stock [Line Items]
Common stock, par value					$ 0.01
2020 At-the-Market Offering | Maximum | Common Stock
Class Of Stock [Line Items]
Aggregate sale price of common stock					$ 225,000,000
2016 LTIP
Class Of Stock [Line Items]
Common stock, shares, issued										147,532
Common stock, shares, issued										839,788		839,788
Common stock, par value									$ 0.0001
Number of shares authorized to issue									2,100,000
2016 LTIP | Restricted Stock Units
Class Of Stock [Line Items]
Equity-based compensation expense										$ 1,900,000	$ 1,600,000
Dividends earned on restricted stock units										$ 1,200,000		$ 1,200,000
2016 LTIP | Restricted Stock Units | Director
Class Of Stock [Line Items]
Vesting period description										annually
2016 LTIP | Restricted Stock Units | Directors, Officers, Employees and Certain Key Employees of Adviser
Class Of Stock [Line Items]
Restricted stock units, granted	142,159	204,663	116,852			168,183	186,662
2016 LTIP | Minimum [Member] | Restricted Stock Units | Officers Employees And Certain Key Employees Of Adviser
Class Of Stock [Line Items]
Restricted stock units, vesting period										3 years
2016 LTIP | Maximum | Restricted Stock Units | Officers Employees And Certain Key Employees Of Adviser
Class Of Stock [Line Items]
Restricted stock units, vesting period										5 years