CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Income
Interest and fees on loans	$ 1,033,993	$ 734,474	$ 680,876
Interest and dividends on investment securities:
Taxable	87,306	72,676	58,143
Tax-exempt	21,504	15,399	15,537
Dividends	13,209	9,812	6,206
Interest on other short-term investments	3,236	1,793	1,126
Total interest income	1,159,248	834,154	761,888
Interest on deposits:
Savings, NOW and money market	108,394	55,300	39,787
Time	81,959	42,546	37,775
Interest on short-term borrowings	45,930	18,034	12,022
Interest on long-term borrowings and junior subordinated debentures	65,762	58,227	59,190
Total interest expense	302,045	174,107	148,774
Net Interest Income	857,203	660,047	613,114
Provision for credit losses	32,501	9,942	11,869
Net Interest Income After Provision for Credit Losses	824,702	650,105	601,245
Non-Interest Income
Insurance commissions	15,213	18,156	19,106
(Losses) gains on securities transactions, net	(2,342)	(20)	777
Fees from loan servicing	9,319	7,384	6,441
Gains on sales of loans, net	20,515	20,814	22,030
Bank owned life insurance	8,691	7,338	6,694
Other	43,206	24,967	21,988
Total non-interest income	134,052	111,706	108,260
Non-Interest Expense
Salary and employee benefits expense	333,816	263,337	243,222
Net occupancy and equipment expense	108,763	92,243	87,140
FDIC insurance assessment	28,266	19,821	20,100
Amortization of other intangible assets	18,416	10,016	11,327
Professional and legal fees	34,141	25,834	17,755
Amortization of tax credit investments	24,200	41,747	34,744
Telecommunication expenses	12,102	9,921	10,021
Other	69,357	46,154	51,816
Total non-interest expense	629,061	509,073	476,125
Income Before Income Taxes	329,693	252,738	233,380
Income tax expense	68,265	90,831	65,234
Net Income	261,428	161,907	168,146
Dividends on preferred stock	12,688	9,449	7,188
Net Income Available to Common Shareholders	$ 248,740	$ 152,458	$ 160,958
Earnings Per Common Share:
Basic (in usd per share)	$ 0.75	$ 0.58	$ 0.63
Diluted (in usd per share)	0.75	0.58	0.63
Cash dividends declared per common share (in usd per share)	$ 0.44	$ 0.44	$ 0.44
Weighted Average Number of Common Shares Outstanding:
Basic (in shares)	331,258,964	264,038,123	254,841,571
Diluted (in shares)	332,693,718	264,889,007	255,268,336
Trust and Investment Services
Non-Interest Income
Services	$ 12,633	$ 11,538	$ 10,345
Deposit Account
Non-Interest Income
Services	$ 26,817	$ 21,529	$ 20,879