Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid- in Capital	Common Shares Held in Deferred Compensation Plan	Deferred Compensation Plan	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2018		61,013,711
Beginning balance at Dec. 31, 2018	$ 1,247,797	$ 610	$ 1,233,763			$ 14,185	$ (761)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,532					15,532
Issuance of common stock, net of issuance costs (in shares)		2,184,888
Issuance of common stock, net of issuance costs	87,924	$ 22	87,902
Repurchase and cancellation of common stock related to employee awards (in shares)		(99,999)
Repurchase and cancellation of common stock related to employee awards	(3,959)		(3,959)
Issuance of restricted stock (in shares)		30,294
Stock-based compensation	928		928
Common stock dividends	(15,109)					(15,109)
Other comprehensive income	63						63
Ending balance (in shares) at Mar. 31, 2019		63,128,894
Ending balance at Mar. 31, 2019	1,333,176	$ 632	1,318,634			14,608	(698)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payments of Stock Issuance Costs	$ 1,427
Dividends per share, common stock (in dollars per share)	$ 0.24
Beginning balance (in shares) at Dec. 31, 2018		61,013,711
Beginning balance at Dec. 31, 2018	$ 1,247,797	$ 610	1,233,763			14,185	(761)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 25,911
Issuance of common stock, net of issuance costs (in shares)	4,364,071
Ending balance (in shares) at Jun. 30, 2019		65,495,713
Ending balance at Jun. 30, 2019	$ 1,436,178	$ 656	1,426,860			9,268	(606)
Beginning balance (in shares) at Mar. 31, 2019		63,128,894
Beginning balance at Mar. 31, 2019	1,333,176	$ 632	1,318,634			14,608	(698)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 10,379					10,379
Issuance of common stock, net of issuance costs (in shares)	2,375,270	2,386,470
Issuance of common stock, net of issuance costs	$ 106,982	$ 24	106,958
Repurchase and cancellation of common stock related to employee awards (in shares)		(19,651)
Repurchase and cancellation of common stock related to employee awards	0		0
Issuance of restricted stock	1,268		1,268
Stock-based compensation	(15,719)					(15,719)
Other comprehensive income	92						92
Ending balance (in shares) at Jun. 30, 2019		65,495,713
Ending balance at Jun. 30, 2019	1,436,178	$ 656	1,426,860			9,268	(606)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payments of Stock Issuance Costs	$ 1,718
Dividends per share, common stock (in dollars per share)	$ 0.24
Beginning balance at Dec. 31, 2019	$ 1,517,123	$ 673	1,514,266			2,621	(437)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	12,856					12,856
Issuance of common stock, net of issuance costs (in shares)		562,521
Issuance of common stock, net of issuance costs	29,651	$ 4	29,647
Repurchase and cancellation of common stock related to employee awards (in shares)		(4,510)
Repurchase and cancellation of common stock related to employee awards	(240)		(240)
Issuance of restricted stock (in shares)		20,501
Stock-based compensation	1,573		1,573
Common stock dividends	(18,314)					(18,314)
Deposits to deferred compensation plan (in shares)		(135,494)
Deposits to deferred compensation plan	0		7,346	$ 135,494	$ (7,346)
Other comprehensive income	73						73
Ending balance (in shares) at Mar. 31, 2020		67,695,805
Ending balance at Mar. 31, 2020	1,542,722	$ 677	1,552,592	135,494	(7,346)	(2,837)	(364)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payments of Stock Issuance Costs	$ 426
Dividends per share, common stock (in dollars per share)	$ 0.27
Beginning balance at Dec. 31, 2019	$ 1,517,123	$ 673	1,514,266			2,621	(437)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	43,560
Ending balance (in shares) at Jun. 30, 2020		68,322,213
Ending balance at Jun. 30, 2020	1,589,266	$ 684	1,587,057	139,224	(7,546)	9,389	(318)
Beginning balance (in shares) at Mar. 31, 2020		67,695,805
Beginning balance at Mar. 31, 2020	1,542,722	$ 677	1,552,592	135,494	(7,346)	(2,837)	(364)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30,704					30,704
Issuance of common stock, net of issuance costs (in shares)		630,490
Issuance of common stock, net of issuance costs	32,075	$ 7	32,068
Forfeiture of common stock related to employee awards (in shares)		(352)
Stock-based compensation	2,197		2,197
Common stock dividends	(18,478)					(18,478)	0
Deposits to deferred compensation plan (in shares)		(3,730)
Deposits to deferred compensation plan	0		200	3,730	(200)
Other comprehensive income	46						46
Ending balance (in shares) at Jun. 30, 2020		68,322,213
Ending balance at Jun. 30, 2020	1,589,266	$ 684	$ 1,587,057	$ 139,224	$ (7,546)	$ 9,389	$ (318)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payments of Stock Issuance Costs	$ 630
Dividends per share, common stock (in dollars per share)	$ 0.27