Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Property and equipment, accumulated depreciation	$ 95,588	$ 92,933
Intangible assets, amortization	$ 1,400	$ 1,400
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	86,209,338	85,953,253
Common stock, shares outstanding	69,061,469	70,151,357
Treasury stock, shares	17,147,869	15,801,896