Stockholders' Equity - At-the-Market Offerings - Additional Information (Details) - At-the-Market Offerings - Class A Common Stock - USD ($) $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended	3 Months Ended
	Mar. 12, 2019	May 31, 2019	Mar. 31, 2019	May 16, 2019
Class Of Stock [Line Items]
Gross proceeds from issuance of common stock		$ 82.9	$ 100.0
Number of shares Issued		1.0	1.4
Average selling price per share		$ 82.90	$ 72.00
Stock Issuance Costs		$ 1.6	$ 2.0
Maximum aggregate offering shares of common stock				1.0
Maximum
Class Of Stock [Line Items]
Gross proceeds from issuance of common stock	$ 100.0