Equity Offerings - Narrative (Details) - Distribution Agreement - USD ($) $ / shares in Units, shares in Thousands		3 Months Ended
	Nov. 03, 2017	Mar. 31, 2019	Mar. 31, 2020
Subsidiary, Sale of Stock [Line Items]
Maximum aggregate offering price	$ 125,000,000.0
Gross proceeds from sales of common stock		$ 20,600,000
Issuance costs on sales of common stock		$ 400,000
Number of shares sold (in shares)		243
Price per share sold (in dollars per share)		$ 84.98
Aggregate value of shares available to be offered			$ 31,500,000