Derivatives - Fair Value of Derivative Contracts (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Assets	$ 41,488,000	$ 72,926,000
Liabilities	17,948,000	25,661,000
Notional amounts	1,830,454,000	3,271,250,000
Rate lock commitments
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Assets	21,034,000	32,035,000
Liabilities	2,977,000	12,124,000
Notional amounts	296,972,000	1,396,827,000
Nasdaq Forwards
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Assets	12,822,000	26,502,000
Liabilities	0	0
Notional amounts	174,000,000	267,480,000
Forward sale contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Assets	7,632,000	14,389,000
Liabilities	14,971,000	13,537,000
Notional amounts	$ 1,359,482,000	$ 1,606,943,000

Nominal or face amount used to calculate payments on the derivative asset.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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Fair value as of the balance sheet date of derivative instrument not designated as hedging instrument and classified as an asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624163-113959

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Fair value as of the balance sheet date of derivative instrument not designated as hedging instrument and classified as a liability.

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