CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash Flows From Operating Activities:
Net income (loss)	$ 1,298,205	$ 764,102
Adjustments to reconcile net income (loss) to net cash flows from operating activities:
Depreciation and amortization	540,959	625,625
Realized and unrealized losses (gains) on investments	(13,153)	(44,467)
Non-cash, stock-based compensation	24,897	20,619
Deferred tax expense (benefit)	308,610	558,423
Other, net	(78,481)	17,976
Changes in current assets and current liabilities, net	(65,303)	284,805
Net cash flows from operating activities	2,015,734	2,227,083
Cash Flows From Investing Activities:
Purchases of marketable investment securities	(801,916)	(282,919)
Sales and maturities of marketable investment securities	675,162	107,768
Purchases of property and equipment	(282,805)	(324,105)
Capitalized interest related to FCC authorizations (Note 2)	(765,239)	(769,046)
Purchases of FCC authorizations, including deposits (Note 9)		(4,711,154)
Purchases of strategic investments		(90,381)
Other, net	16,773	22,666
Net cash flows from investing activities	(1,158,025)	(6,047,171)
Cash Flows From Financing Activities:
Proceeds from issuance of convertible notes		1,000,000
Redemption and repurchases of senior notes	(1,088,392)	(900,000)
Repayment of long-term debt and capital lease obligations	(32,651)	(32,409)
Payments made to parent of transferred businesses		(7,098)
Net proceeds from Class A common stock options exercised and stock issued under the Employee Stock Purchase Plan	16,300	24,171
Debt issuance costs		(6,158)
Other, net	(2,760)	(349)
Net cash flows from financing activities	(1,107,503)	78,157
Net increase (decrease) in cash, cash equivalents, restricted cash and cash equivalents	(249,794)	(3,741,931)
Cash, cash equivalents, restricted cash and cash equivalents, beginning of period (Note 5)	1,479,901	5,325,184
Cash, cash equivalents, restricted cash and cash equivalents, end of period (Note 5)	$ 1,230,107	$ 1,583,253