Fair Value Measurements - Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financial assets:
Trading securities	$ 393,581	$ 689,576
Available for sale, at fair value (amortized cost of $0 and $984,211, respectively)	972,318	911,493
Equity securities	107	166
Financial liabilities:
Securities sold, not yet purchased	22,768	43,817
Recurring
Financial assets:
Trading securities	393,581	689,576
Available for sale, at fair value (amortized cost of $0 and $984,211, respectively)	972,318	911,493
Equity securities	107	166
Loans held for sale	2,089,969	1,935,713
Derivative assets	192,729	33,129
MSR asset	30,299	55,504
Financial liabilities:
Securities sold, not yet purchased	22,768	43,817
Derivative liabilities	171,210	17,140
Recurring \| Level 1
Financial assets:
Trading securities	1,485
Equity securities	107	166
Financial liabilities:
Securities sold, not yet purchased	11,333	29,080
Recurring \| Level 2
Financial assets:
Trading securities	392,096	689,576
Available for sale, at fair value (amortized cost of $0 and $984,211, respectively)	972,318	911,493
Loans held for sale	2,010,381	1,868,518
Derivative assets	192,729	33,129
Financial liabilities:
Securities sold, not yet purchased	11,435	14,737
Derivative liabilities	171,210	17,140
Recurring \| Level 3
Financial assets:
Loans held for sale	79,588	67,195
MSR asset	$ 30,299	$ 55,504

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

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Fair value of obligations incurred from short sales.

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Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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