Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income
Loans and lease financing	$ 428,419	$ 405,702	$ 399,209
Available-for-sale securities	83,019	73,615	64,069
Other	7,082	4,529	4,005
Total interest income	518,520	483,846	467,283
Interest expense
Deposits	26,650	22,314	23,262
Short-term borrowings and long-term debt	198	207	223
Total interest expense	26,848	22,521	23,485
Net interest income	491,672	461,325	443,798
Provision for loan and lease losses	8,600	9,900	11,100
Net interest income after provision for loan and lease losses	483,072	451,425	432,698
Noninterest income
Service charges on deposit accounts	38,147	40,850	42,889
Credit and debit card fees	56,071	56,416	56,569
Other service charges and fees	35,355	38,641	37,213
Trust and investment services income	29,440	29,671	27,736
Bank-owned life insurance	15,021	9,976	13,769
Investment securities gains, net	27,277	12,321	20,822
Other	16,290	23,528	10,239
Total noninterest income	217,601	211,403	209,237
Noninterest expense:
Salaries and employee benefits	169,233	170,233	157,096
Contracted services and professional fees	45,345	42,663	37,919
Occupancy	20,116	16,975	22,172
Equipment	16,912	15,836	13,262
Regulatory assessment and fees	12,972	9,490	8,320
Advertising and marketing	6,127	5,472	5,509
Card rewards program	15,513	17,687	18,301
Other	42,626	41,245	35,112
Total noninterest expense	328,844	319,601	297,691
Income before provision for income taxes	371,829	343,227	344,244
Provision for income taxes	141,651	129,447	127,572
Net income	$ 230,178	$ 213,780	$ 216,672
Basic earnings per share (in dollars per share)	$ 1.65	$ 1.53	$ 1.55
Diluted earnings per share (in dollars per share)	1.65	$ 1.53	$ 1.55
Dividends declared per share (in dollars per share)	$ 0.62
Basic weighted-average outstanding shares (in shares)	139,487,762	139,459,620	139,459,620
Diluted weighted-average outstanding shares (in shares)	139,492,608	139,459,620	139,459,620