Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities
Net Income	$ 170,891	$ 159,649	$ 144,050
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	60,503	43,949	40,119
Provision for credit losses	55,752	40,441	38,648
Deferred tax expense	15,250	550	44,113
Net securities gains	(712)	(822)	(11,717)
Tax benefit of stock-based compensation	(1,813)	(28)	(2,714)
Loans originated for sale	(713,087)	(445,558)	(162,010)
Loans sold	716,705	455,623	168,533
Gain on sale of loans	(10,746)	(8,666)	(5,565)
Net change in:
Interest receivable	(5,214)	(4,688)	(2,211)
Interest payable	(150)	760	(875)
Securities classified as trading in business combination and sold			241,595
Bank owned life insurance	(5,373)	(6,397)	(10,401)
Other, net	10,702	(11,333)	(34,746)
Net cash flows provided by operating activities	292,708	223,480	446,819
Investing Activities
Net increase in loans and leases	(816,093)	(985,999)	(1,192,618)
Securities available for sale:
Purchases	(1,066,361)	(421,901)	(829,800)
Sales	615,199	33,499	175,872
Maturities	543,923	284,483	303,875
Securities held to maturity:
Purchases	(1,063,273)	(465,597)	(475,579)
Sales			4,570
Maturities	357,111	277,967	213,730
Purchase of bank owned life insurance	(16,587)	(72,688)	(16)
Withdrawal/surrender of bank owned life insurance		72,664	21,968
Increase in premises and equipment	(59,327)	(9,723)	(20,238)
Net cash received in business combinations	245,762	144,629	59,980
Net cash flows used in investing activities	(1,259,646)	(1,142,666)	(1,738,256)
Financing Activities
Demand (non-interest-bearing and interest-bearing) and savings accounts	933,793	1,259,765	652,808
Time deposits	(119,734)	(166,283)	(292,026)
Short-term borrowings	251,713	7,238	789,318
Proceeds from issuance of long-term borrowings	46,357	134,953	385,656
Repayment of long-term borrowings	(173,477)	(34,968)	(96,906)
Net proceeds from issuance of common stock	18,472	12,731	12,857
Tax benefit of stock-based compensation	1,813	28	2,714
Cash dividends paid:
Preferred stock	(8,041)	(8,041)	(8,352)
Common stock	(101,670)	(84,511)	(81,220)
Net cash flows provided by financing activities	849,226	1,120,912	1,364,849
Net (Decrease) Increase in Cash and Cash Equivalents	(117,712)	201,726	73,412
Cash and cash equivalents at beginning of year	489,119	287,393	213,981
Cash and Cash Equivalents at End of Year	$ 371,407	$ 489,119	$ 287,393