Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Interest and Dividend Income, Operating	$ 224,237	$ 189,182	$ 157,824	$ 144,872	$ 145,169	$ 142,866	$ 140,204	$ 138,293	$ 716,115	$ 566,532	$ 598,878
Interest Expense	73,716	35,996	16,286	11,696	11,851	12,570	13,627	15,714	137,694	53,762	131,380
Interest Income (Expense), Net	150,521	153,186	141,538	133,176	133,318	130,296	126,577	122,579	578,421	512,770	467,498
PROVISION (CREDIT) FOR CREDIT LOSSES	8,200	9,200	3,200	(11,000)	1,500	(10,000)	(7,000)	3,300	9,600	(12,200)	95,000
Interest Income (Expense), after Provision for Loan Loss	142,321	143,986	138,338	144,176	131,818	140,296	133,577	119,279	568,821	524,970	372,498
Noninterest Income	12,110	13,355	12,746	13,186	13,097	10,617	11,076	8,804	51,397	43,594	53,432
Noninterest Expense	84,518	83,914	80,365	75,373	74,236	75,502	73,123	70,431	324,170	293,292	283,639
Pretax income	69,913	73,427	70,719	81,989	70,679	75,411	71,530	57,652	296,048	275,272	142,291
Income tax provision	18,210	19,679	18,631	21,251	19,056	19,912	17,767	13,965	77,771	70,700	30,776
Net Income (Loss) Attributable to Parent	$ 51,703	$ 53,748	$ 52,088	$ 60,738	$ 51,623	$ 55,499	$ 53,763	$ 43,687	$ 218,277	$ 204,572	$ 111,515
Basic EPS - common stock (in dollars per share)	$ 0.43	$ 0.45	$ 0.43	$ 0.51	$ 0.43	$ 0.45	$ 0.44	$ 0.35	$ 1.82	$ 1.67	$ 0.90
Diluted EPS - common stock (in dollars per share)	$ 0.43	$ 0.45	$ 0.43	$ 0.50	$ 0.43	$ 0.45	$ 0.43	$ 0.35	$ 1.81	$ 1.66	$ 0.90