Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Statement of Cash Flows [Abstract]
Net cash provided by operating activities	$ 58,876	$ 63,306
Investing Activities
Proceeds from maturities, repayments, and calls of securities available-for-sale	174,937	148,842
Proceeds from sales of securities available-for-sale	40,043	47,320
Purchases of securities available-for-sale	(532,934)	(159,252)
Proceeds from maturities, repayments, and calls of securities held-to-maturity	4,360	3,447
Purchases of securities held-to-maturity	(16)	(1,184)
Purchases of FHLB stock	(3,651)	(1,190)
Net increase in loans	(432,283)	(128,883)
Proceeds from claims on BOLI, net of premiums paid	1,599	1,021
Proceeds from sales of OREO	3,852	10,584
Proceeds from sales of premises, furniture, and equipment	3,213	195
Purchases of premises, furniture, and equipment	(7,536)	(4,386)
Net cash received from acquisitions	57,347	0
Net cash used in investing activities	(691,069)	(83,486)
Financing Activities
Net increase in deposit accounts	278,657	324,913
Net increase in borrowed funds	282,232	51,042
Payments for the maturity of subordinated debt	(38,500)	0
Cash dividends paid	(14,123)	(13,232)
Restricted stock activity	(2,248)	(2,766)
Excess tax benefit related to share-based compensation	362	794
Net cash provided by financing activities	506,380	360,751
Net (decrease) increase in cash and cash equivalents	(125,813)	340,571
Cash and cash equivalents at beginning of period	381,202	606,262
Cash and cash equivalents at end of period	255,389	946,833
Supplemental Disclosures of Cash Flow Information:
Income taxes paid	7,427	7,953
Interest paid to depositors and creditors	13,269	11,476
Dividends declared, but unpaid	7,595	7,023
Common stock issued for acquisitions, net of issuance costs	54,896	0
Non-cash transfers of loans to OREO	3,675	4,657
Non-cash transfers of loans held-for-investment to loans held-for-sale	$ 63,709	$ 23,012