SBM Acquisition - Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($)		Oct. 16, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
Equity interest issued			$ 110,551,000	$ 0	$ 0
OREO			1,304,000	1,587,000	2,195,000	$ 1,313,000
Goodwill			95,657,000	44,806,000	$ 44,806,000
Loans and Leases Receivable, Allowance			$ 21,166,000	$ 21,116,000
SBM Financial, Inc. [Member]
Business Acquisition [Line Items]
Cash		$ 26,100,000
Equity interest issued		108,561,000
Total consideration paid		136,700,000
Loans and loans held for sale		627,893,000
Cash and due from banks		86,042,000
Investments		39,742,000
Deferred tax assets		25,116,000
Premises and equipment		23,944,000
OREO		729,000
Core deposit intangible assets		6,608,000
Other assets		5,251,000
Deposits and borrowings		721,186,000
Other liabilities		8,314,000
Total identified assets acquired and liabilities assumed, at fair value		85,825,000
Goodwill		$ 50,851,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares		2,749,762
Share Price		$ 39.48
Loans and Leases Receivable, Allowance		$ 6,500,000
Deferred Costs		4,600,000
Loans held for sale gross, adjustment		13,400,000
Write-off of deferred tax assets operating losses, adjustment		2,400,000
Deferred tax assets, acquired assets and assumed liabilities, adjustment		381,000
Deferred tax assets, increase of 1.0% on acquired deferred tax assets, adjustment		720,000
Deferred tax assets, other deferred tax assets, adjustment		147,000
Nonqualified Stock Options [Member] | SBM Financial, Inc. [Member]
Business Acquisition [Line Items]
Equity interest issued		1,990,000
Predecessor [Member] | SBM Financial, Inc. [Member]
Business Acquisition [Line Items]
Loans and loans held for sale		639,390,000
Cash and due from banks		86,042,000
Investments		39,716,000
Deferred tax assets		26,293,000
Premises and equipment		16,851,000
OREO		2,530,000
Core deposit intangible assets		0
Other assets		5,421,000
Deposits and borrowings		719,640,000
Other liabilities		8,512,000
Total identified assets acquired and liabilities assumed, at fair value		88,091,000
Estimate of Fair Value Measurement [Member] | SBM Financial, Inc. [Member]
Business Acquisition [Line Items]
Loans and loans held for sale	[1]	(11,497,000)
Cash and due from banks		0
Investments		26,000
Deferred tax assets	[2]	(1,177,000)
Premises and equipment		7,093,000
OREO		(1,801,000)
Core deposit intangible assets		6,608,000
Other assets		(170,000)
Deposits and borrowings		1,546,000
Other liabilities		(198,000)
Total identified assets acquired and liabilities assumed, at fair value		$ (2,266,000)

[1] (1)The presented fair value adjustment on loans and loans held for sale is net of the acquired allowance for loan losses of $6.5 million and acquired net deferred origination costs of $4.6 million as these balances were eliminated in purchase accounting. The fair value adjustment on loans and loans held for sale before adjustment of the acquired allowance for loan losses and net deferred origination costs was a discount on the acquired balance of $13.4 million.

[2] (2) Adjustment to deferred tax assets does not represent a fair value adjustment as deferred tax assets (or liabilities) are not recorded at fair value in accordance with GAAP. The adjustment reflects the write-off of certain acquired federal net operating losses and state tax credits that will not be utilized of $2.4 million (post-tax), deferred tax assets generated as acquired assets and assumed liabilities are recorded at fair value of $381,000, an increase in deferred tax assets of $720,000 due to an increase of 1.0% on acquired deferred tax assets, and other deferred tax asset increases of $147,000.