Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest income:
Loans and leases	$ 193,539	$ 203,781	$ 189,961	$ 599,417	$ 459,625
Investment securities	13,955	14,570	12,331	40,720	35,140
Deposits in financial institutions	178	104	64	304	314
Total interest income	207,672	218,455	202,356	640,441	495,079
Interest expense:
Deposits	10,400	11,233	8,822	32,112	17,360
Borrowings	72	88	74	395	352
Subordinated debentures	4,680	4,582	4,614	13,787	9,973
Total interest expense	15,152	15,903	13,510	46,294	27,685
Net interest income	192,520	202,552	188,846	594,147	467,394
Provision for credit losses	8,746	6,529	5,050	31,709	9,436
Net interest income after provision for credit losses	183,774	196,023	183,796	562,438	457,958
Non-interest income:
Service charges on deposit accounts	2,601	2,612	2,725	7,787	8,446
Other commissions and fees	6,376	7,123	6,371	18,895	14,046
Leased equipment income	5,475	5,375	5,615	16,232	11,287
Gain on sale of loans and leases	27	163	973	190	594
Gain (loss) on sale of securities	655	(186)	0	3,744	4,841
FDIC loss sharing expense, net	(4,449)	(5,107)	(7,415)	(13,955)	(27,370)
Other income	5,073	9,643	8,045	23,359	17,640
Total noninterest income	15,758	19,623	16,314	56,252	29,484
Non-interest expense:
Compensation	48,152	49,033	45,861	144,922	119,569
Occupancy	10,762	10,588	11,188	31,950	29,861
Data processing	4,322	4,402	3,929	13,032	10,568
Other professional services	3,396	3,332	3,687	9,949	8,053
Insurance and assessments	3,805	4,716	3,020	11,546	7,792
Intangible asset amortization	1,497	1,502	1,608	4,500	4,649
Leased equipment depreciation	3,162	3,103	2,961	9,368	6,056
Foreclosed assets expense (income), net	4,521	(2,340)	4,827	2,517	3,463
Acquisition, integration and reorganization costs	747	900	5,193	3,647	93,635
Other expense	9,775	10,040	12,649	28,344	30,641
Total noninterest expense	90,139	85,276	94,923	259,775	314,287
Earnings from continuing operations before taxes	109,393	130,370	105,187	358,915	173,155
Income tax expense	(39,777)	(45,287)	(42,911)	(131,137)	(73,744)
Net earnings from continuing operations	69,616	85,083	62,276	227,778	99,411
Loss from discontinued operations before taxes	0	0	(8)	0	(2,572)
Income tax benefit	0	0	3	0	1,067
Net loss from discontinued operations	0	0	(5)	0	(1,505)
Net earnings	$ 69,616	$ 85,083	$ 62,271	$ 227,778	$ 97,906
Earnings Per Share, Basic [Abstract]
Net earnings from continuing operations (usd per share)	$ 0.68	$ 0.83	$ 0.60	$ 2.21	$ 1.20
Net earnings (usd per share)	0.68	0.83	0.60	2.21	1.18
Earnings Per Share, Diluted [Abstract]
Net earnings from continuing operations (usd per share)	0.68	0.83	0.60	2.21	1.20
Net earnings (usd per share)	0.68	0.83	0.60	2.21	1.18
Dividends [Abstract]
Dividends declared per share (usd per share)	$ 0.5	$ 0.5	$ 0.25	$ 1.50	$ 0.75