Stockholders Equity - Additional Information (Details) $ in Thousands	1 Months Ended						12 Months Ended			63 Months Ended
	Aug. 31, 2018 shares	Mar. 31, 2018 shares	Jul. 31, 2017 shares	Jan. 31, 2017 shares	Nov. 30, 2014 shares	Apr. 30, 2014 shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)	Dec. 31, 2019 shares
Class Of Stock [Line Items]
Treasury stock, shares							2,757,558	1,426,115		2,757,558
Treasury stock shares acquired (in shares)							1,331,443	718,699
Treasury stock shares acquired | $							$ 51,175	$ 33,473	$ 12,258
Number of units held by noncontrolling interest holders							12,958,022	13,053,465		12,958,022
Group LP
Class Of Stock [Line Items]
Noncontrolling interests (as a percent)							21.00%	22.00%		21.00%
Class A Common Stock
Class Of Stock [Line Items]
Aggregate stock issuance (in shares)						15,263,653
Common stock, shares issued							52,773,617	47,031,095		52,773,617
Treasury stock, shares							2,757,558	1,426,115		2,757,558
Common stock, shares outstanding							50,016,059	45,604,980		50,016,059
Increase in shares outstanding	4,685,217	4,689,295	5,680,903	5,356,876	4,511,058					24,923,349
Number of shares of common stock to be issued upon exchange of a partnership unit							1			1
Class A Common Stock | Group LP
Class Of Stock [Line Items]
Common stock, shares outstanding							50,016,059	45,604,980		50,016,059
Class B Common Stock
Class Of Stock [Line Items]
Common stock, shares issued							10,397,915	10,493,358		10,397,915
Common stock, shares outstanding							10,397,915	10,493,358		10,397,915
Increase in shares outstanding						36,158,698
Ratio of subscription price to the initial public offering price of shares of common stock					0.00055
Dividends payable ratio to outstanding shares of publicly traded common stock					0.00055