Consolidated Statement Of Shareholders' Deficit - 9 months ended Sep. 30, 2017 - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member] Class A Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Total
BALANCE at Dec. 31, 2016	$ 1,210	$ 2,010,520	$ (3,637,467)	$ (370,184)	$ (1,995,921)
BALANCE, Shares at Dec. 31, 2016	121,004
Net income			95,994		95,994
Common stock issued in connection with stock purchase/option plans	$ 7	45,098			45,105
Common stock issued in connection with stock purchase/option plans, Shares	711
Non-cash stock compensation		29,347			29,347
Common stock issued in connection with acquisitions	$ 5	63,308			63,313
Common stock issued in connection with acquisitions, Shares	488
Repurchase and retirement of common stock	$ (38)		(523,332)		(523,370)
Repurchase and retirement of common stock, Shares	(3,775)
Foreign currency translation adjustments				27,734	27,734
BALANCE at Sep. 30, 2017	$ 1,184	$ 2,148,273	$ (4,064,805)	$ (342,450)	$ (2,257,798)
BALANCE, Shares at Sep. 30, 2017	118,428