Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income (loss)	$ 11,918	$ 21,317	$ 20,486	$ 21,552	$ 18,935	$ 19,325	$ 53,721	$ 59,812
Less: Net income allocated to participating securities	(116)			(75)			(350)	(224)
Numerator for basic earnings available to common stockholders	11,802			21,477			53,371	59,588
Numerator for basic and diluted earnings available to common stockholders	$ 11,802			$ 21,477			$ 53,371	$ 59,588
Denominator:
Weighted-average basic common shares outstanding (in shares)	96,297			95,214			95,922	95,195
Diluted market condition stock awards (in shares)	0			0			15	0
Weighted-average diluted common shares outstanding (in shares)	96,297			95,214			95,937	95,195
Earnings per common share, basic (in dollars per share)	$ 0.12			$ 0.23			$ 0.56	$ 0.63
Earnings per common share, diluted (in dollars per share)	$ 0.12			$ 0.23			$ 0.56	$ 0.63
Antidilutive unvested restricted stock awards and performance awards excluded from the computation	535			300			436	300