CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 594,104	$ 250,762	$ 176,099
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation of property and equipment	97,103	98,529	103,433
Amortization of definite-lived intangible assets	178,822	183,795	161,454
Amortization of program contract costs and net realizable value adjustments	115,523	127,880	124,619
Loss on extinguishment of debt, non-cash portion	1,404	3,875	0
Stock-based compensation	15,886	16,939	18,315
Deferred tax (benefit) provision	(159,462)	6,118	(28,446)
(Gain) loss on the sale of assets	(278,608)	(6,029)	278
Changes in assets and liabilities, net of effects of acquisitions and dispositions:
Increase in accounts receivable	(41,908)	(71,718)	(38,666)
Net change in net income taxes payable/receivable	(43,374)	18,814	3,203
Increase in prepaid expenses and other current assets	(9,409)	(969)	(3,474)
Increase (decrease) in accounts payable and accrued liabilities	34,857	60,086	(15,902)
Payments on program contracts payable	(111,470)	(111,506)	(109,057)
Other, net	37,636	15,190	11,071
Net cash flows from operating activities	431,104	591,766	402,927
CASH FLOWS USED IN INVESTING ACTIVITIES:
Acquisition of property and equipment	(83,812)	(94,465)	(91,421)
Acquisition of businesses, net of cash acquired	(271,273)	(425,857)	(17,011)
Proceeds from the sale of assets	192,634	16,396	23,650
Purchase of alarm monitoring contracts	(5,682)	(40,206)	(39,185)
Investments in equity and cost method investees	(55,129)	(51,247)	(44,715)
Distributions from equity and cost method investees	12,918	6,786	21,749
Loans to affiliates	19,500	(19,500)	0
Other, net	(7,181)	2,090	(4,378)
Net cash flow used in investing activities	(198,025)	(606,003)	(151,311)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Proceeds from notes payable, commercial bank financing and capital leases	166,797	1,024,912	382,887
Repayments of notes payable, commercial bank financing and capital leases	(336,501)	(671,215)	(395,147)
Proceeds from the sale of Class A Common Stock	487,883	0	0
Repurchase of outstanding Class A Common Stock	(30,287)	(136,283)	(28,823)
Dividends paid on Class A and Class B Common Stock	(71,364)	(65,909)	(62,733)
Payments for deferred financing costs	(731)	(15,681)	(3,847)
Noncontrolling interests distributions	(22,416)	(10,464)	(9,918)
Other, net	(5,118)	(1,111)	(1,745)
Net cash flows from (used in) financing activities	188,263	124,249	(119,326)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	421,342	110,012	132,290
CASH AND CASH EQUIVALENTS, beginning of year	259,984	149,972	17,682
CASH AND CASH EQUIVALENTS, end of year	$ 681,326	$ 259,984	$ 149,972