CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows From Operating Activities:
Net income (loss)	$ 361,299	$ 385,321
Adjustments to reconcile net income (loss) to net cash flows from operating activities:
Depreciation and amortization	153,139	192,972
Realized and unrealized losses (gains) on investments	(2,617)	36,722
Non-cash, stock-based compensation	11,537	9,060
Deferred tax expense (benefit)	53,921	92,064
Other, net	(4,469)	(32,426)
Changes in current assets and current liabilities, net	160,119	67,838
Net cash flows from operating activities	732,929	751,551
Cash Flows From Investing Activities:
Purchases of marketable investment securities	(145,162)	(9,253)
Sales and maturities of marketable investment securities	513,033	313,567
Purchases of property and equipment	(120,859)	(70,521)
Capitalized interest related to FCC authorizations (Note 2)	(289,775)	(294,003)
Other, net	2,495	3,613
Net cash flows from investing activities	(40,268)	(56,597)
Cash Flows From Financing Activities:
Redemption and repurchases of senior notes	(22,365)	(56,473)
Repayment of long-term debt and finance lease obligations	(6,632)	(10,458)
Net proceeds from Class A common stock options exercised and stock issued under the Employee Stock Purchase Plan	4,750	7,991
Other, net	29,000	(159)
Net cash flows from financing activities	4,753	(59,099)
Net increase (decrease) in cash, cash equivalents, restricted cash and cash equivalents	697,414	635,855
Cash, cash equivalents, restricted cash and cash equivalents, beginning of period (Note 5)	887,924	1,479,901
Cash, cash equivalents, restricted cash and cash equivalents, end of period (Note 5)	$ 1,585,338	$ 2,115,756