Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Interest income
Interest and fees on loans	$ 183,292	$ 156,818
Interest on investment securities:
Taxable	20,501	12,419
Tax-exempt	7,170	5,556
Dividends on nonmarketable equity securities	1,738	1,901
Interest on deposits with the Federal Reserve Bank and other banks and federal funds sold	1,280	1,240
Total interest income	213,981	177,934
Interest expense
Interest on deposits	38,998	15,917
Interest on collateralized customer deposits	627	524
Interest on short-term borrowings	9,178	8,166
Interest on long-term borrowings	2,354	1,464
Total interest expense	51,157	26,071
Net interest income	162,824	151,863
Provision for loan losses	2,059	6,256
Net interest income after provision for loan losses	160,765	145,607
Noninterest income
Net gain on sale of loans and other mortgage banking revenue	894	12,535
Net gain on sale of investment securities	87	0
Other	5,213	7,491
Total noninterest income	24,857	40,554
Operating expenses
Salaries, wages and employee benefits	60,017	55,557
Occupancy	8,277	8,011
Equipment and software	6,979	7,659
Outside processing and service fees	11,726	10,356
Merger expenses	5,424	0
Other	16,592	20,027
Total operating expenses	109,015	101,610
Income before income taxes	76,607	84,551
Income tax expense	13,665	12,955
Net income	$ 62,942	$ 71,596
Earnings per common share:
Basic earnings per common share (dollars per share)	$ 0.88	$ 1.01
Diluted earnings per common share (dollars per share)	$ 0.87	$ 0.99
Service charges and fees on deposit accounts
Noninterest income
Noninterest income	$ 7,967	$ 9,434
Wealth management revenue
Noninterest income
Noninterest income	5,872	6,311
Other charges and fees for customer services
Noninterest income
Noninterest income	$ 4,824	$ 4,783