CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($)	Total	Common Stock [Member]	Common Stock Including Additional Paid in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance, beginning of the period, shares at Dec. 31, 2018		35,182,772
Balance, beginning of the period at Dec. 31, 2018	$ 1,478,595,000		$ 1,337,436,000	$ 134,055,000	$ 7,104,000
Net income	146,278,000			146,278,000
Other comprehensive income (loss)	26,152,000				26,152,000
Accrual of dividends on common stock	(93,495,000)			(93,495,000)
Stock Repurchased and Retired During Period, Shares		1,000,000
Cash paid for repurchase of common stock	(53,922,000)		(53,922,000)
Issuance of unvested restricted common stock, net, shares		(9,547)
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	5,226,000		5,226,000
Balance, end of the period, shares at Dec. 31, 2019		35,751,576
Balance, end of the period at Dec. 31, 2019	$ 1,594,034,000		1,373,940,000	186,838,000	33,256,000
Cumulative dividends declared per common share (in dollars per share)	$ 2.64
Net income	$ 115,928,000			115,928,000
Other comprehensive income (loss)	35,813,000				35,813,000
Accrual of dividends on common stock	(44,235,000)			(44,235,000)
Stock Repurchased and Retired During Period, Shares		624,780
Cash paid for repurchase of common stock	(31,775,000)		(31,775,000)
Issuance of unvested restricted common stock, net, shares		32,404
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	7,714,000		7,714,000
Balance, end of the period, shares at Dec. 31, 2020		35,159,200
Balance, end of the period at Dec. 31, 2020	1,666,264,000		1,349,879,000	247,316,000	69,069,000
Cumulative effect, Accounting Standard Update Adopted	$ (11,215,000)			(11,215,000)
Cumulative dividends declared per common share (in dollars per share)	$ 1.23
Net income	$ 201,048,000			201,048,000
Other comprehensive income (loss)	(68,885,000)				(68,885,000)
Accrual of dividends on common stock	(57,602,000)			(57,602,000)
Stock Repurchased and Retired During Period, Shares		1,050,000
Cash paid for repurchase of common stock	(56,528,000)		(56,528,000)
Issuance of unvested restricted common stock, net, shares		143,432
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	6,030,000		6,030,000
Balance, end of the period, shares at Dec. 31, 2021		34,252,632
Balance, end of the period at Dec. 31, 2021	$ 1,690,327,000		$ 1,299,381,000	$ 390,762,000	$ 184,000
Cumulative dividends declared per common share (in dollars per share)	$ 1.64