Gains From Mortgage Banking Activities/Originations, Net - Summary of Gains From Mortgage Banking Activities/Originations, Net (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Mortgage Banking [Abstract]
Loan originations related fees and sales premiums, net	$ 17,817	$ 15,952
Fair value of expected net future cash flows from servicing recognized at commitment, net	21,097	29,310
Gains from mortgage banking activities/originations, net	$ 38,914	$ 45,262

The gains (losses) included in earnings that represent the difference between the sale price and the carrying value of loans made to finance real estate acquisitions. This element refers to the gain (loss) and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration