Condensed Consolidated Statements of Stockholders' Deficit (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] ASC 2016-09 [Member]	Retained Deficit [Member]	Retained Deficit [Member] ASC 2016-09 [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]
BALANCE at Dec. 31, 2015	$ (552,138)	$ 85	$ 2,193,193		$ (2,607,415)		$ (72,736)	$ (65,265)
BALANCE, shares at Dec. 31, 2015		83,366,888
Net income	77,534				77,534
Dividends declared	(38,187)				(38,187)
Foreign currency translation adjustment, net	(5,398)						(5,398)
Purchase of stock at cost	(21,961)							(21,961)
Purchase of stock at cost, shares		(1,000,000)
Executive Deferred Compensation Plan activity	1,522		1,522
Executive Deferred Compensation Plan activity, shares		12,964
Shares issued from the Employee Stock Purchase Plan	3,460	$ 1	3,459
Shares issued from the Employee Stock Purchase Plan, shares		182,285
Stock options exercised including related tax benefits	649		649
Stock options exercised including related tax benefits, shares		29,475
Issuance of shares (vesting of restricted shares and Director awards)	(63)		(63)
Issuance of shares (vesting of restricted shares and Director awards), shares		23,975
Share-based compensation	12,150		12,150
BALANCE at Jun. 30, 2016	(522,432)	$ 86	2,210,910		(2,568,068)		(78,134)	(87,226)
BALANCE, shares at Jun. 30, 2016		82,615,587
BALANCE at Dec. 31, 2016	(441,849)	$ 86	2,223,379		(2,490,455)		(87,633)	(87,226)
BALANCE, shares at Dec. 31, 2016		83,264,912
Net income	98,860				98,860
Dividends declared	(19,013)				(19,013)
Foreign currency translation adjustment, net	21,587						21,587
Unrealized loss on interest rate derivatives, net	(1,408)						(1,408)
Executive Deferred Compensation Plan activity	3,241		3,241
Executive Deferred Compensation Plan activity, shares		32,090
Shares issued from the Employee Stock Purchase Plan	3,615	$ 1	3,614
Shares issued from the Employee Stock Purchase Plan, shares		173,249
Stock options exercised including related tax benefits	510		510
Stock options exercised including related tax benefits, shares		20,549
Issuance of shares (vesting of restricted shares and Director awards)	(870)		(870)
Issuance of shares (vesting of restricted shares and Director awards), shares		77,852
Share-based compensation	10,824		10,824
BALANCE at Jun. 30, 2017	$ (324,503)	$ 87	$ 2,240,801		$ (2,410,711)		$ (67,454)	$ (87,226)
BALANCE, shares at Jun. 30, 2017		83,568,652
Cumulative effect of adoption of ASC 2016-09				$ 103		$ (103)