CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock Issued	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Balances at Dec. 31, 2015	$ 310,803	$ 140,503	$ (760,299)	$ 170,699	$ 1,236,355	$ (515,688)	$ 39,233
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(79,753)				(85,667)		5,914
Cash dividends declared:
Noncontrolling interests	(1,702)						(1,702)
Total other comprehensive income (loss), net of deferred income taxes of $(14,196), $(1,384) and $(2,427) in 2016, 2017, and 2018 respectively	(93,614)					(91,034)	(2,580)
Purchase of subsidiary shares from noncontrolling interest	(4,731)			(5,128)			397
Vesting of restricted stock units and other stock grants, net 80,598 shares, 269,924 shares and 384,134 shares in 2016, 2017 and 2018, respectively	(1,164)	122	(92)	(1,194)
Amortization of unearned stock-based compensation, net of forfeitures	7,724			7,724
Balances at Dec. 31, 2016	137,563	140,625	(760,391)	172,101	1,150,688	(606,722)	41,262
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	11,844				7,822		4,022
Cash dividends declared:
Noncontrolling interests	(2,445)						(2,445)
Total other comprehensive income (loss), net of deferred income taxes of $(14,196), $(1,384) and $(2,427) in 2016, 2017, and 2018 respectively	63,184					60,140	3,044
Purchase of subsidiary shares from noncontrolling interest	(3,436)			(2,242)			(1,194)
Sale of investment in consolidated subsidiary	25						25
Stock appreciation rights exercised, net 8,965 shares and net 28,108 shares in 2017 and 2018, respectively	(63)	16	(63)	(16)
Vesting of restricted stock units and other stock grants, net 80,598 shares, 269,924 shares and 384,134 shares in 2016, 2017 and 2018, respectively	(1,625)	469	(1,625)	(469)
Amortization of unearned stock-based compensation, net of forfeitures	9,721			9,721
Balances at Dec. 31, 2017	215,165	141,110	(762,079)	180,201	1,157,801	(546,582)	44,714
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standard (See Note 2)					(100)
Net income (loss)	145,013				137,057		7,956
Cash dividends declared:
Noncontrolling interests	(5,534)						(5,534)
Total other comprehensive income (loss), net of deferred income taxes of $(14,196), $(1,384) and $(2,427) in 2016, 2017, and 2018 respectively	(21,505)					(19,005)	(2,500)
Purchase of subsidiary shares from noncontrolling interest	477						477
Stock appreciation rights exercised, net 8,965 shares and net 28,108 shares in 2017 and 2018, respectively	(282)	50	(282)	(50)
Vesting of restricted stock units and other stock grants, net 80,598 shares, 269,924 shares and 384,134 shares in 2016, 2017 and 2018, respectively	(3,449)	682	(3,449)	(682)
Treasury shares repurchased, 596,632 shares in 2015	(30,011)		(30,011)
Amortization of unearned stock-based compensation, net of forfeitures	11,128			11,128
Balances at Dec. 31, 2018	$ 313,376	$ 141,842	$ (795,821)	$ 190,597	$ 1,298,752	$ (567,107)	$ 45,113