Portfolio Loans - Summary of Allowance for Loan Losses by Portfolio Class and Category (Details) - Non-Covered Loans - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2015	Mar. 31, 2015
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2014		$ 30,185
Provision charged to expense	$ 2,150	1,580
Losses charged off	(2,596)	(2,568)
Recoveries	1,923	1,091
Balance at March 31, 2015	31,765
Commercial and industrial
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2014	17,112	17,004
Provision charged to expense	2,927	823
Losses charged off	(1,578)	(1,484)
Recoveries	420	769
Balance at March 31, 2015	18,881	17,112
CRE - owner occupied
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2014	3,577	3,625
Provision charged to expense	(347)	(175)
Losses charged off	0	0
Recoveries	1,287	127
Balance at March 31, 2015	4,517	3,577
Commercial Real Estate Investor Owned
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2014	4,615	4,598
Provision charged to expense	(519)	(12)
Losses charged off	(664)	0
Recoveries	13	29
Balance at March 31, 2015	3,445	4,615
Construction and land development
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2014	2,694	1,720
Provision charged to expense	(91)	914
Losses charged off	(350)	0
Recoveries	115	60
Balance at March 31, 2015	2,368	2,694
Residential real estate
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2014	1,857	2,830
Provision charged to expense	100	74
Losses charged off	0	(1,073)
Recoveries	87	26
Balance at March 31, 2015	2,044	1,857
Consumer and other
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2014	433	408
Provision charged to expense	80	(44)
Losses charged off	(4)	(11)
Recoveries	1	80
Balance at March 31, 2015	$ 510	$ 433