CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Common Class A Common Stock	Common Class B Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2017	$ 52	$ 24	$ 2,215,109	$ (1,970,097)	$ (449,369)	$ (51)	$ (204,332)
Changes in stockholders' equity
Net loss				(38,941)			(38,941)
Other comprehensive income (loss)					5,550		5,550
Issuance of shares	1		(1)
Stock compensation expense			741				741
Treasury stock, acquired						(307)	(307)
Stockholders' Equity Attributable to Parent, Ending Balance at Apr. 01, 2018	53	24	2,215,849	(2,011,706)	(443,819)	(358)	(239,957)
Changes in stockholders' equity
Cumulative effect adjustment of new accounting pronouncement				(2,668)			(2,668)
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 30, 2018	53	24	2,216,681	(1,954,132)	(604,289)	(2)	(341,665)
Changes in stockholders' equity
Net loss				(41,956)			(41,956)
Other comprehensive income (loss)					22,552		22,552
Issuance of shares	2		(2)
Stock compensation expense			663				663
Treasury stock, acquired						(268)	(268)
Stockholders' Equity Attributable to Parent, Ending Balance at Mar. 31, 2019	$ 55	$ 24	$ 2,217,342	(1,996,065)	$ (581,737)	$ (270)	(360,651)
Changes in stockholders' equity
Cumulative effect adjustment of new accounting pronouncement				$ 23			$ 23