Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income (loss)	$ 21,317	$ 20,486	$ 18,935	$ 19,325	$ 41,803	$ 38,260
Less: Net income allocated to participating securities	(116)		(75)		(234)	(148)
Numerator for basic earnings available to common stockholders	21,201		18,860		41,569	38,112
Numerator for basic and diluted earnings available to common stockholders	$ 21,201		$ 18,860		$ 41,569	$ 38,112
Denominator:
Weighted-average basic common shares outstanding (in shares)	96,082		95,208		95,732	95,185
Dilutive market condition stock awards	38		0		23	0
Weighted-average diluted common shares outstanding (in shares)	96,120		95,208		95,755	95,185
Earnings per common share, basic (in dollars per share)	$ 0.22		$ 0.20		$ 0.43	$ 0.40
Earnings per common share, diluted (in dollars per share)	$ 0.22		$ 0.20		$ 0.43	$ 0.40