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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 portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock.

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Face (par) amount of debt instrument at time of issuance.

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Fair value, after the effects of master netting arrangements, of a financial liability or 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 liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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FAIR VALUE MEASUREMENTS (Details) - USD ($)	Mar. 31, 2020	Feb. 29, 2020	Dec. 31, 2019
Fair Value Assets
Capped call transactions	$ 33,308,000		$ 0
Convertible debt fair value	533,000,000	$ 515,900,000
Convertible Debt
Fair Value Assets
Capped call transactions		51,900,000
Face amount		$ 600,000,000
Cash equivalents
Fair Value Assets
Cash equivalents	460,475,000		0
Investments in privately-held companies
Fair Value Assets
Investments in privately-held companies	6,338,000		4,871,000
Level 1
Fair Value Assets
Capped call transactions	0		0
Level 1 \| Cash equivalents
Fair Value Assets
Cash equivalents	460,475,000		0
Level 1 \| Investments in privately-held companies
Fair Value Assets
Investments in privately-held companies	0		0
Level 2
Fair Value Assets
Capped call transactions	33,308,000		0
Level 2 \| Cash equivalents
Fair Value Assets
Cash equivalents	0		0
Level 2 \| Investments in privately-held companies
Fair Value Assets
Investments in privately-held companies	0		0
Level 3
Fair Value Assets
Capped call transactions	0		0
Level 3 \| Cash equivalents
Fair Value Assets
Cash equivalents	0		0
Level 3 \| Investments in privately-held companies
Fair Value Assets
Investments in privately-held companies	$ 6,338,000		$ 4,871,000