Mergers and Acquisitions - Pro Forma Combined Condensed Consolidated Financial Information (Details) - Brand Mortgage Group, LLC - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Net interest income - pro forma	$ 113,147	$ 111,618
Noninterest income - pro forma	35,885	42,497
Noninterest expense - pro forma	88,832	99,774
Net income - pro forma	$ 45,110	$ 40,296
Earnings per share - pro forma:
Basic (usd per share)	$ 0.77	$ 0.69
Diluted (usd per share)	$ 0.77	$ 0.69

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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