Fair Value Measurements - Notional Amounts and Fair Values of Derivatives by Product (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative liability, notional	$ 5,229,373	$ 5,317,805
Derivative liability, Fair Value	1,414	6,780
Other Contracts | TBAs
Derivatives, Fair Value [Line Items]
Derivatives asset, Notional		729,500
Derivatives asset, Fair Value		4,873
Derivative liability, notional	13,245	729,500
Derivative liability, Fair Value	124	4,873
Other Contracts | Foreign exchange forward contracts
Derivatives, Fair Value [Line Items]
Derivative liability, notional		200
Derivative liability, Fair Value		4
Other Contracts | Auction Rate Securities Purchase Commitment
Derivatives, Fair Value [Line Items]
Derivative liability, notional	7,128	7,305
Derivative liability, Fair Value	1,023	1,096
Commodity Contracts | Futures
Derivatives, Fair Value [Line Items]
Derivative liability, notional	5,209,000	4,580,800	[1]
Derivative liability, Fair Value	$ 267	$ 807	[1]

[1] the year ended December 31, 2019, the diluted net income per share computation does not include the anti-dilutive effect of 7,628 shares of Class A Stock granted under share-based compensation arrangements (4,050 and 10,592 shares for the years ended December 31, 2018 and 2017, respectively).(2)Represents net income from discontinued operations, net of tax divided by weighted average number of shares outstanding.