Consolidated Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income		$ 581,793	$ 409,182
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		146,835	150,223
Non-cash interest expense, net of amortization of premium		4,713	4,231
Provision for doubtful accounts		23,944	27,377
Amortization of deferred income related to equity method investment		(1,388)	(1,388)
Loss on unconsolidated entity investments, net		64	2,183
Gain on fair value instrument		(117,449)	0
Dividend received from unconsolidated entity investment		1,366	3,606
Share-based payment expense		70,448	59,697
Deferred income taxes		134,044	220,415
Changes in operating assets and liabilities:
Receivables		(29,364)	(38,063)
Inventory		1,232	2,492
Related party, net		(1,722)	(5,756)
Prepaid expenses and other current assets		(177)	(6,617)
Other long-term assets		8,356	5,937
Accounts payable and accrued expenses		87,857	(69,078)
Accrued interest		(9,399)	(7,042)
Deferred revenue		85,100	30,779
Other long-term liabilities		7,863	4,358
Net cash provided by operating activities		994,116	792,536
Cash flows from investing activities:
Additions to property and equipment		(174,273)	(119,517)
Purchases of other investments		(7,138)	(7,355)
Acquisition of business, net of cash acquired		0	(107,056)
Investments in related parties and other equity investees		(6,138)	(302,526)
Repayment from (loan to) related party		3,242
Repayment from (loan to) related party			(130,794)
Net cash used in investing activities		(184,307)	(667,248)
Cash flows from financing activities:
Taxes paid in lieu of shares issued for stock-based compensation		(71,501)	(22,595)
Revolving credit facility, net of deferred financing costs		(302,611)	610,000
Principal payments of long-term borrowings		(7,717)	(6,000)
Common stock repurchased and retired		(334,215)	(783,824)
Dividends paid		(98,684)	(93,638)
Net cash used in financing activities		(814,728)	(296,057)
Net decrease in cash, cash equivalents and restricted cash		(4,919)	(170,769)
Cash, cash equivalents and restricted cash at beginning of period		79,374	223,828
Cash, cash equivalents and restricted cash at end of period	[1]	74,455	53,059
Cash paid during the period for:
Interest, net of amounts capitalized		178,850	164,147
Income taxes paid		5,625	12,264
Non-cash investing and financing activities:
Capital lease obligations incurred to acquire assets		499	0
Change in treasury stock not yet settled		17,154	8,123
Other comprehensive loss (income), net of tax benefit		17,826	(2,746)
Issuance of common stock as part of recapitalization of Sirius XM Canada		$ 0	$ 178,850

[1] The following table reconciles cash, cash equivalents and restricted cash per the statement of cash flows to the balance sheet. The restricted cash balances are primarily due to letters of credit which have been issued to the landlords of leased office space. The terms of the letters of credit primarily extend beyond one year. June 30, 2018 December 31, 2017 June 30, 2017 December 31, 2016Cash and cash equivalents$63,516 $69,022 $42,738 $213,939Restricted cash included in Prepaid expenses and other current assets150 244 432 —Restricted cash included in Other long-term assets10,789 10,108 9,889 9,889Total cash, cash equivalents and restricted cash at end of period$74,455 $79,374 $53,059 $223,828