Marketable Investment Securities, Restricted Cash and Cash Equivalents, and Other Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Feb. 28, 2017
Marketable Investment Securities, Restricted Cash and Cash Equivalents and Other Investment Securities:
Current marketable investment securities	$ 48,995	$ 132,593
Restricted marketable investment securities			$ 390
Total marketable investment securities	48,995	132,593	390
Restricted cash and cash equivalents	58,255	58,323	60,677
Other investment securities	98,050	97,306	106,874
Total other investment securities	98,050	97,306	106,874
Total marketable investment securities, restricted cash and cash equivalents, and other investment securities	$ 205,300	$ 288,222	$ 167,941
NagraStar L.L.C
Marketable Investment Securities, Restricted Cash and Cash Equivalents and Other Investment Securities:
Ownership interest in equity method investment		50.00%		50.00%

Marketable investment securities, restricted cash and cash equivalent and other investment securities.

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The amount of marketable securities pledged as collateral noncurrent.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Amount of investment in marketable security.

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Amount of investment in marketable security, classified as current.

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Amount of investments classified as other.

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Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, 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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