Consolidated Statement Of Shareholders' Deficit - 6 months ended Jun. 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			46,832		46,832
Common stock issued in connection with stock purchase/option plans	$ 6	33,462			33,468
Common stock issued in connection with stock purchase/option plans, Shares	573
Non-cash compensation		19,803			19,803
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	$ (11)		(144,427)		(144,438)
Repurchase and retirement of common stock, Shares	(1,084)
Foreign currency translation adjustments				(8,738)	(8,738)
BALANCE at Jun. 30, 2017	$ 1,210	$ 2,127,093	$ (3,735,062)	$ (378,922)	$ (1,985,681)
BALANCE, Shares at Jun. 30, 2017	120,981