Stockholders' Equity Stockholders' Equity - Follow-on Public Offering (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Stock price at grant date (in dollars per share)	$ 124.00
Proceeds from a public offering, net of underwriting discount	$ 979,000	$ 980,000	$ 0	$ 0
Common Class A | Follow-on Public Offering
Class of Stock [Line Items]
Shares sold (in shares)	8,064,515
Common Class A | Over-Allotment Option, FPO
Class of Stock [Line Items]
Shares sold (in shares)	1,051,893