Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 22,336	$ 18,577
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	2,316	2,007
PROVISION FOR LOAN LOSSES	1,690	401
Securities premium amortization (discount accretion), net	4,652	4,208
Gain on sale of assets, net	(451)	(74)
Change in loans held for sale	(3,174)	1,334
Change in other assets	8,174	8,732
Change in other liabilities	7,842	7,440
Total adjustments	21,049	24,048
Net cash provided by operating activities	43,385	42,625
CASH FLOWS FROM INVESTING ACTIVITIES:
Net decrease in interest-bearing time deposits in banks	1,891	3,833
Activity in available-for-sale securities:
Sales	904	5,227
Maturities	49,491	94,803
Purchases	(142,638)	(236,984)
Activity in held-to-maturity securities - maturities	102	158
Net increase in loans	(7,150)	(51,454)
Purchases of bank premises and equipment and other assets	(1,909)	(4,567)
Proceeds from sale of other assets	839	1,015
Net cash used in investing activities	(98,470)	(187,969)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in noninterest-bearing deposits	27,147	(73,868)
Net increase (decrease) in interest-bearing deposits	72,059	(8,590)
Net increase (decrease) in short-term borrowings	(80,668)	3,648
Common stock transactions:
Proceeds from stock issuances	714	613
Dividends paid	(8,318)
Net cash provided by (used in) financing activities	10,934	(78,197)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(44,151)	(223,541)
CASH AND CASH EQUIVALENTS, beginning of period	212,012	360,739
CASH AND CASH EQUIVALENTS, end of period	167,861	137,198
SUPPLEMENTAL INFORMATION AND NONCASH TRANSACTIONS
Interest paid	1,055	953
Federal income tax paid
Transfer of loans to foreclosed assets	158	39
Investment securities purchased but not settled	$ 3,387	$ 21,095