CONDENSED STATEMENT OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Preferred Stock	Treasury Stock	Additional Paid in Capital	Retained Earnings
Balance at beginning of period at Dec. 31, 2018		$ 533	$ 0	$ (38,030)	$ 239,827	$ 510,282
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock purchase				(1,970)
Stock compensation					2,435
Dividends paid						(235,210)
Other					(1,242)	105
Net income	$ 235,928					235,928
Balance at end of period at Jun. 30, 2019	712,658	533	0	(40,000)	241,020	511,105
Balance at beginning of period at Mar. 31, 2019		533	0	(40,000)	240,408	618,123
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock purchase				0
Stock compensation					1,327
Dividends paid						(232,604)
Other					(715)	105
Net income	125,481					125,481
Balance at end of period at Jun. 30, 2019	712,658	533	0	(40,000)	241,020	511,105
Balance at beginning of period at Dec. 31, 2019	765,582	533	0	(50,576)	243,932	571,693
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock purchase				0
Stock compensation					3,466
Dividends paid						(5,197)
Other					(1,272)	0
Net income	12,384					12,384
Balance at end of period at Jun. 30, 2020	774,963	533	0	(50,576)	246,126	578,880
Balance at beginning of period at Mar. 31, 2020		533	0	(50,576)	244,525	590,640
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock purchase				0
Stock compensation					1,862
Dividends paid						(2,599)
Other					(261)	0
Net income	(9,161)					(9,161)
Balance at end of period at Jun. 30, 2020	$ 774,963	$ 533	$ 0	$ (50,576)	$ 246,126	$ 578,880