Equity - At-The-Market Offering (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
ATM Program Activity
Gross proceeds		$ 195,924	$ 179,882
Commissions paid on stock issuance	$ 404
Prior ATM Program
ATM Program Activity
Number of shares (shares)		2,459
Average sales price per share (usd per share)		$ 19.48
Gross proceeds		$ 47,893
Commissions paid on stock issuance		$ 600