Fair Value of Financial Instruments - Schedule of Debt Instruments Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Unsecured senior notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unsecured Senior Notes	$ 55,000	$ 55,000
Unsecured senior notes | Unsecured senior notes | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unsecured Senior Notes	54,881	54,765
Unsecured senior notes | Unsecured senior notes | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unsecured Senior Notes	0	0
Unsecured senior notes | Unsecured senior notes | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unsecured Senior Notes	0	0
Unsecured senior notes | Unsecured senior notes | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unsecured Senior Notes	55,000	54,600
Wells Fargo revolving credit facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Wells Fargo Credit Agreement	16,829	39,527
Wells Fargo revolving credit facility | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Wells Fargo Credit Agreement	16,829	39,527
Wells Fargo revolving credit facility | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Wells Fargo Credit Agreement	0	0
Wells Fargo revolving credit facility | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Wells Fargo Credit Agreement	16,829	39,527
Wells Fargo revolving credit facility | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Wells Fargo Credit Agreement	$ 0	$ 0