CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows From Operating Activities:
Net income (loss)	$ 845,607	$ 448,837
Adjustments to reconcile net income (loss) to net cash flows from operating activities:
Depreciation and amortization	365,674	416,301
Realized and unrealized losses (gains) on investments	17,425	(4,759)
Non-cash, stock-based compensation	18,772	11,863
Deferred tax expense (benefit)	196,707	347,550
Other, net	(65,625)	41,716
Changes in current assets and current liabilities, net	(53,222)	231,588
Net cash flows from operating activities	1,325,338	1,493,096
Cash Flows From Investing Activities:
Purchases of marketable investment securities	(523,948)	(72,224)
Sales and maturities of marketable investment securities	461,152	92,671
Purchases of property and equipment	(168,119)	(212,387)
Capitalized interest related to FCC authorizations (Note 2)	(472,773)	(452,421)
Purchases of FCC authorizations, including deposits (Note 9)		(4,711,154)
Purchases of strategic investments		(90,381)
Other, net	6,225	10,229
Net cash flows from investing activities	(697,463)	(5,435,667)
Cash Flows From Financing Activities:
Proceeds from issuance of convertible notes (Note 8)		1,000,000
Redemption and repurchases of senior notes	(1,088,392)
Repayment of long-term debt and capital lease obligations	(20,152)	(20,086)
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	11,730	16,778
Debt issuance costs		(6,158)
Other, net	(2,760)
Net cash flows from financing activities	(1,099,574)	983,436
Net increase (decrease) in cash, cash equivalents, restricted cash and cash equivalents	(471,699)	(2,959,135)
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)	$ 1,008,202	$ 2,366,049