Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest income
Interest and fees on loans	$ 165,388	$ 141,314	$ 322,206	$ 273,799
Interest on investment securities:
Taxable	14,706	7,125	27,125	11,881
Tax-exempt	5,998	4,426	11,554	8,661
Dividends on nonmarketable equity securities	2,189	1,246	4,090	1,867
Interest on deposits with the Federal Reserve Bank, other banks and Federal funds sold	1,301	1,022	2,541	1,821
Total interest income	189,582	155,133	367,516	298,029
Interest expense
Interest on deposits	19,707	10,582	35,624	19,498
Interest on collateralized customer deposits	641	196	1,165	346
Interest on short-term borrowings	10,408	4,463	18,574	5,971
Interest on long-term borrowings	1,289	1,944	2,753	4,169
Total interest expense	32,045	17,185	58,116	29,984
Net interest income	157,537	137,948	309,400	268,045
Provision for loan losses	9,572	6,229	15,828	10,279
Net interest income after provision for loan losses	147,965	131,719	293,572	257,766
Noninterest income
Net gain on sale of loans and other mortgage banking revenue	8,844	9,879	21,379	19,039
Net gain on sale of investment securities	3	77	3	167
Other	7,494	6,143	14,985	12,181
Total noninterest income	38,018	41,568	78,572	79,578
Operating expenses
Salaries, wages and employee benefits	56,148	52,247	111,705	112,141
Occupancy	7,679	8,745	15,690	16,137
Equipment and software	8,276	8,149	15,935	16,666
Outside processing and service fees	10,673	8,924	21,029	16,435
Merger expenses	0	465	0	4,632
Other	21,785	19,707	41,812	36,422
Total operating expenses	104,561	98,237	206,171	202,433
Income before income taxes	81,422	75,050	165,973	134,911
Income tax expense	12,434	23,036	25,389	35,293
Net income	$ 68,988	$ 52,014	$ 140,584	$ 99,618
Earnings per common share:
Basic earnings per common share (dollars per share)	$ 0.97	$ 0.73	$ 1.97	$ 1.41
Diluted earnings per common share (dollars per share)	0.96	0.73	1.95	1.39
Cash dividends declared per common share (dollars per share)	$ 0.28	$ 0.27	$ 0.56	$ 0.54
Service charges and fees on deposit accounts
Noninterest income
Noninterest income	$ 8,615	$ 8,777	$ 17,078	$ 16,781
Wealth management revenue
Noninterest income
Noninterest income	7,188	6,958	13,499	12,785
Other charges and fees for customer services
Noninterest income
Noninterest income	$ 5,874	$ 9,734	$ 11,628	$ 18,625