Financial Instruments - Schedule of Assets, Liabilities, and Equity Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
U.S. treasury securities	$ 70,029
U.S. treasury securities	30,978
Fair Value, Measurements, Recurring
Assets
Loans held for sale	21,985	$ 4,913
Derivative asset	500	254
Total assets	344,934	430,943
Liabilities
Total liabilities	115	141
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Loans held for sale	0	0
Derivative asset	0	0
Total assets	322,449	425,776
Liabilities
Total liabilities	0	0
Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets
Loans held for sale	21,985	4,913
Derivative asset	4	0
Total assets	21,989	4,913
Liabilities
Total liabilities	57	141
Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Assets
Loans held for sale	0	0
Derivative asset	496	254
Total assets	496	254
Liabilities
Total liabilities	58	0
U.S. treasury securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
U.S. treasury securities	70,029
U.S. treasury securities	30,978
U.S. treasury securities \| Fair Value, Measurements, Recurring
Assets
U.S. treasury securities	70,029
U.S. treasury securities	30,978
U.S. treasury securities \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
U.S. treasury securities	70,029
U.S. treasury securities	30,978
U.S. treasury securities \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets
U.S. treasury securities	0
U.S. treasury securities	0
U.S. treasury securities \| Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Assets
U.S. treasury securities	0
U.S. treasury securities	0
Forward sales commitments \| Fair Value, Measurements, Recurring
Assets
Derivative asset	4
Liabilities
Derivative liability	57	141
Forward sales commitments \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Derivative asset	0
Liabilities
Derivative liability	0	0
Forward sales commitments \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets
Derivative asset	4
Liabilities
Derivative liability	57	141
Forward sales commitments \| Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Assets
Derivative asset	0
Liabilities
Derivative liability	0	0
Interest rate lock commitments \| Fair Value, Measurements, Recurring
Assets
Derivative asset	496	254
Liabilities
Derivative liability	58
Interest rate lock commitments \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Derivative asset	0	0
Liabilities
Derivative liability	0
Interest rate lock commitments \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets
Derivative asset	0	0
Liabilities
Derivative liability	0
Interest rate lock commitments \| Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Assets
Derivative asset	496	254
Liabilities
Derivative liability	58
Money market funds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Money market funds		425,776
Money market funds \| Fair Value, Measurements, Recurring
Assets
Money market funds	221,442	425,776
Money market funds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Money market funds	221,442	425,776
Money market funds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets
Money market funds	0	0
Money market funds \| Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Assets
Money market funds	$ 0	$ 0

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value of financial and nonfinancial obligations.

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