Condensed Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income:
Loans and leases	$ 240,811	$ 247,851	$ 275,978	$ 750,940	$ 834,443
Investment securities	24,443	26,038	28,806	77,927	87,434
Deposits in financial institutions	654	186	2,424	2,448	4,423
Total interest income	265,908	274,075	307,208	831,315	926,300
Interest expense:
Deposits	9,887	13,075	40,703	51,209	113,658
Borrowings	27	1,319	6,852	8,124	21,772
Subordinated debentures	4,670	5,402	7,417	16,632	22,860
Total interest expense	14,584	19,796	54,972	75,965	158,290
Net interest income	251,324	254,279	252,236	755,350	768,010
Provision for credit losses	97,000	120,000	7,000	329,000	19,000
Net interest income after provision for credit losses	154,324	134,279	245,236	426,350	749,010
Noninterest income:
Other commissions and fees	10,541	10,111	10,855	30,373	33,453
Leased equipment income	9,900	12,037	9,615	34,188	28,079
Service charges on deposit accounts	2,570	2,004	3,525	7,232	11,026
Gain on sale of loans and leases	35	346	765	468	1,091
Gain on sale of securities	5,270	7,715	908	13,167	25,261
Other income	9,936	6,645	7,761	20,782	16,476
Total noninterest income	38,252	38,858	33,429	106,210	115,386
Noninterest expense:
Compensation	75,131	61,910	71,424	198,323	211,225
Occupancy	14,771	14,494	14,089	43,472	42,866
Data processing	6,505	7,102	7,044	20,061	20,786
Leased equipment depreciation	7,057	7,102	5,951	21,364	17,160
Intangible asset amortization	3,751	3,882	4,833	11,581	14,573
Other professional services	4,713	4,146	4,400	13,117	13,542
Insurance and assessments	3,939	9,373	4,100	17,561	12,236
Customer related expense	4,762	4,408	3,539	13,102	9,887
Loan expense	3,499	3,379	3,628	9,528	9,964
Acquisition, integration and reorganization costs	0	0	0	0	618
Foreclosed assets expense (income), net	335	(146)	8	255	(109)
Goodwill impairment	0	0	0	1,470,000	0
Other expense	8,939	11,315	7,793	29,973	25,775
Total noninterest expense	133,402	126,965	126,809	1,848,337	378,523
Earnings (loss) before income taxes	59,174	46,172	151,856	(1,315,777)	485,873
Income tax expense	(13,671)	(12,968)	(41,830)	(38,627)	(135,118)
Net earnings (loss)	$ 45,503	$ 33,204	$ 110,026	$ (1,354,404)	$ 350,755
Earnings (loss) per share:
Basic (usd per share)	$ 0.38	$ 0.28	$ 0.92	$ (11.60)	$ 2.91
Diluted (usd per share)	$ 0.38	$ 0.28	$ 0.92	$ (11.60)	$ 2.91