Stockholders' Equity - Preferred Stock (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Jul. 26, 2018	Feb. 28, 2017	Jul. 31, 2018	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Issuance of common stock in initial public offering				$ 133,805
Preferred shares outstanding (in shares)					0	0
Preferred stock, dividend rate		6.00%
Preferred stock, dividends declared (in dollars per share)				$ 0.308
Preferred stock, cash dividend				$ 11,300
Series A Preferred Stock
Class of Stock [Line Items]
Issuance of shares (in shares)		35,845,001
Issuance of common stock in initial public offering		$ 335,000
Conversion of Series A to Common Shares
Class of Stock [Line Items]
Number of shares converted (in shares)	37,700,000		37,700,000
Common shares issued on conversion (in shares)	39,600,000		39,600,000