CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income
Beginning balance - Shares at Dec. 31, 2018		6,000,000	50,201,127			417
Beginning balance - Amount at Dec. 31, 2018	$ 2,500,394	$ 150,000	$ 502	$ 967,890	$ 1,381,492	$ (8)	$ 518
Comprehensive income:
Net income	82,839				82,839
Change in unrealized gain (loss) on available-for-sale securities, net of taxes	(43)						(43)
Comprehensive income/(loss)	82,796
Stock-based compensation expense recognized in earnings	2,423			2,423
Preferred stock dividend	(2,438)				(2,438)
Issuance of stock related to stock-based awards - Shares			54,133
Issuance of stock related to stock-based awards - Amount	(1,233)		$ 1	(1,234)
Issuance of common stock related to warrants - shares			8,768
Issuance of common stock related to warrants	0
Ending balance - Amount at Mar. 31, 2019	2,581,942	$ 150,000	$ 503	969,079	1,461,893	$ (8)	475
Ending balance - Shares at Mar. 31, 2019		6,000,000	50,264,028			417
Beginning balance - Shares at Dec. 31, 2019		6,000,000	50,338,158			417
Beginning balance - Amount at Dec. 31, 2019	2,832,258	$ 150,000	$ 503	978,205	1,694,608	$ (8)	8,950
Comprehensive income:
Net income	(16,687)				(16,687)
Change in unrealized gain (loss) on available-for-sale securities, net of taxes	(4,181)						(4,181)
Comprehensive income/(loss)	(20,868)
Stock-based compensation expense recognized in earnings	3,227			3,227
Preferred stock dividend	(2,438)				(2,438)
Issuance of stock related to stock-based awards - Shares			70,037
Issuance of stock related to stock-based awards - Amount	(1,492)		$ 1	(1,493)
Ending balance - Amount at Mar. 31, 2020	$ 2,803,533	$ 150,000	$ 504	$ 979,939	$ 1,668,329	$ (8)	$ 4,769
Ending balance - Shares at Mar. 31, 2020		6,000,000	50,408,195			417