Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
NET EARNINGS	$ 52,505	$ 49,303
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	5,687	5,074
PROVISION FOR LOAN LOSSES	4,386	2,844
Securities premium amortization (discount accretion), net	13,912	13,164
Gain on sale of assets, net	(1,706)	(226)
Deferred federal income tax benefit	(1,288)	(763)
Change in loans held for sale	7,810	(16,741)
Change in other assets	5,861	(15,129)
Change in other liabilities	3,843	8,022
Total adjustments	38,505	(3,755)
Net cash provided by operating activities	91,010	45,548
CASH FLOWS FROM INVESTING ACTIVITIES:
Cash paid for asset acquisition of 4Trust Mortgage, Inc.		(1,931)
Net decrease in interest-bearing time deposits in banks	1,068	11,546
Activity in available-for-sale securities:
Sales	13,382	7,760
Maturities	2,151,678	2,111,206
Purchases	(2,132,087)	(2,448,852)
Activity in held-to-maturity securities - maturities	141	146
Net (increase) decrease in loans	30,500	(13,802)
Purchases of bank premises and equipment and other assets	(12,130)	(6,240)
Proceeds from sale of other assets	2,170	390
Net cash provided by (used in) investing activities	54,722	(339,777)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in noninterest-bearing deposits	(101,140)	4,415
Net decrease in interest-bearing deposits	(32,740)	(27,251)
Net increase (decrease) in short-term borrowings	(58,751)	254,045
Common stock transactions:
Proceeds from stock issuances	936	924
Dividends paid	(21,125)	(17,952)
Net cash provided by (used in) financing activities	(212,820)	214,181
NET DECREASE IN CASH AND CASH EQUIVALENTS	(67,088)	(80,048)
CASH AND CASH EQUIVALENTS, beginning of period	272,886	253,471
CASH AND CASH EQUIVALENTS, end of period	205,798	173,423
SUPPLEMENTAL INFORMATION AND NONCASH TRANSACTIONS:
Interest paid	2,599	1,972
Federal income tax paid	13,874	13,994
Transfer of loans to foreclosed assets	1,692	97
Investment securities purchased but not settled	$ 62,124	$ 15,483