Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest income:
Loans and leases	$ 83,856	$ 85,158	$ 71,631	$ 69,269	$ 657,097	$ 272,726	$ 260,230
Investment securities					47,345	36,923	35,657
Deposits in financial institutions					333	265	228
Total interest income					704,775	309,914	296,115
Interest expense:
Deposits					27,332	7,868	13,271
Borrowings					496	537	2,656
Subordinated debentures					14,570	3,796	3,721
Total interest expense	2,598	2,869	3,158	3,576	42,398	12,201	19,648
Net interest income	81,258	82,289	68,473	65,693	662,377	297,713	276,467
Provision (negative provision) for credit losses	(1,338)	(4,167)	(1,842)	3,137	11,499	(4,210)	(12,819)
Net interest income after provision (negative provision) for credit losses					650,878	301,923	289,286
Noninterest income:
Service charges on deposit accounts					11,233	11,765	12,852
Other commissions and fees					18,602	8,416	8,126
Leased equipment income					16,669	0	0
Gain on sale of loans and leases					601	1,791	2,767
Gain on securities	(272)	5,222	0	409	4,841	5,359	1,239
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net					0	0	(1,115)
FDIC loss sharing expense, net	(10,593)	(7,032)	(5,410)	(3,137)	(31,730)	(26,172)	(10,070)
Other income					21,971	3,085	2,073
Total noninterest income	(3,926)	5,127	203	2,840	42,187	4,244	15,872
Noninterest expense:
Compensation and benefits					165,499	107,067	94,967
Occupancy					40,606	29,459	28,113
Data processing					14,618	9,494	9,120
Other professional services					11,234	6,754	5,903
Insurance and assessments					10,907	5,596	5,284
Intangible asset amortization	16,673	5,450	17,997	692	6,268	5,402	6,326
Leased equipment depreciation					9,159	0	0
Foreclosed assets expense (income), net	(569)	(420)	(14)	(500)	5,401	(1,503)	10,931
Acquisition, integration and reorganization costs	49,984	51,170	46,233	43,991	101,016	40,812	4,089
Debt termination					0	0	22,598
Other expense					44,036	27,606	24,331
Total noninterest expense					408,744	230,687	211,662
Earnings from continuing operations before taxes	12,582	35,383	6,302	21,213	284,321	75,480	93,496
Income tax expense	(9,135)	(11,243)	(1,906)	(7,719)	(113,853)	(30,003)	(36,695)
Net earnings from continuing operations					170,468	45,477	56,801
Loss from discontinued operations before taxes	(578)	39	(81)	0	(2,677)	(620)	0
Income tax benefit	240	(16)	34	0	1,114	258	0
Net loss from discontinued operations	(338)	23	(47)	0	(1,563)	(362)	0
Net earnings	$ 3,109	$ 24,163	$ 4,349	$ 13,494	$ 168,905	$ 45,115	$ 56,801
Net earnings from continuing operations (usd per share)	$ 70	$ 530.00	$ 110.00	$ 370.00	$ 1.94	$ 1.09	$ 1.54
Basic income per share (usd per share)	$ 60	$ 530.00	$ 110.00	$ 370.00	$ 1.92	$ 1.08	$ 1.54
Net earnings from continuing operations (usd per share)	$ 70	$ 530.00	$ 110.00	$ 370.00	$ 1.94	$ 1.09	$ 1.54
Diluted income per share (usd per share)	$ 60	$ 530.00	$ 110.00	$ 370.00	$ 1.92	$ 1.08	$ 1.54
Dividends declared per share (usd per share)					$ 1.25	$ 1.00	$ 0.79