CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash Flows From Operating Activities:
Net income (loss)	$ 1,069,006	$ 567,862
Adjustments to reconcile net income (loss) to net cash flows from operating activities:
Depreciation and amortization	382,970	435,796
Realized and unrealized losses (gains) on investments		(3,117)
Non-cash, stock-based compensation	20,113	8,317
Deferred tax expense (benefit)	45,210	(41,065)
Allowance for credit losses and allowance for doubtful accounts, respectively	15,085	6,165
Other, net	142	69,851
Changes in current assets and current liabilities, net	170,372	(14,641)
Net cash flows from operating activities	1,702,898	1,029,168
Cash Flows From Investing Activities:
(Purchases) Sales and maturities of marketable investment securities, net	(445,675)	153,416
Purchases of property and equipment	(233,261)	(298,595)
Other, net	6,221	71,572
Net cash flows from investing activities	(672,715)	(73,607)
Cash Flows From Financing Activities:
Redemption and repurchases of senior notes	(1,100,000)	(1,317,372)
Proceeds from the issuance of senior notes	1,000,000
Advances to affiliates	(82,415)
Advances from affiliates		332,263
Repayment of long-term debt and finance lease obligations	(38,867)	(23,086)
Debt issuance costs	(1,670)
Other, net		(444)
Net cash flows from financing activities	(222,952)	(1,008,639)
Net increase (decrease) in cash, cash equivalents, restricted cash and cash equivalents	807,231	(53,078)
Cash, cash equivalents, restricted cash and cash equivalents, beginning of period (Note 4)	78,103	130,076
Cash, cash equivalents, restricted cash and cash equivalents, end of period (Note 4)	$ 885,334	$ 76,998