Stockholders' Equity - Summary of Distributions Declared (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash Distributions	$ 16,112	$ 10,480	$ 9,226
Distributions Reinvested	19,446	12,146	10,547
Total Declared	$ 35,558	$ 22,626	$ 19,773
Class AX
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash distributions declared per share (usd per share)	$ 0.63	$ 0.61	$ 0.60
Class TX
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash distributions declared per share (usd per share)	0.52	0.51	0.50
Class IX
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash distributions declared per share (usd per share)	0.60	0.59	0.39
Class T
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash distributions declared per share (usd per share)	0.52	0.51	0
Class S
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash distributions declared per share (usd per share)	0.52	0.51	0
Class D
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash distributions declared per share (usd per share)	0.60	0.59	0
Class I
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash distributions declared per share (usd per share)	$ 0.63	$ 0.61	$ 0

Aggregate dividends declared during the period for each share of common stock outstanding.

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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