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, 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	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 $(1,384) $(2,427) and $690 in 2017, 2018, and 2019 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, net 28,109 and net 11,246 shares in 2017 and 2018 and 2019, respectively	(63)	16	(63)	(16)
Vesting of restricted stock units and other stock grants, net 269,924 shares, 384,134 shares and 196,102 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]
Net income	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 $(1,384) $(2,427) and $690 in 2017, 2018, and 2019 respectively	(21,505)					(19,005)	(2,500)
Purchase of subsidiary shares from noncontrolling interest	477						477
Stock appreciation rights exercised, net 8,965 shares, net 28,109 and net 11,246 shares in 2017 and 2018 and 2019, respectively	(282)	50	(282)	(50)
Vesting of restricted stock units and other stock grants, net 269,924 shares, 384,134 shares and 196,102 shares in 2016, 2017 and 2018, respectively	(3,449)	682	(3,449)	(682)
Treasury shares repurchased, 1,321,072 shares and 1,766,826 shares in 2018 and 2019 respectively	(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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	512,218				503,919		8,299
Cash dividends declared:
Noncontrolling interests	(4,693)						(4,693)
Total other comprehensive income (loss), net of deferred income taxes of $(1,384) $(2,427) and $690 in 2017, 2018, and 2019 respectively	(58)					914	(972)
Purchase of subsidiary shares from noncontrolling interest	4,026						4,026
Noncontrolling Interest, Decrease from Deconsolidation	(3,694)						(3,694)
Stock appreciation rights exercised, net 8,965 shares, net 28,109 and net 11,246 shares in 2017 and 2018 and 2019, respectively	(117)	20	(117)	(20)
Vesting of restricted stock units and other stock grants, net 269,924 shares, 384,134 shares and 196,102 shares in 2016, 2017 and 2018, respectively	(2,882)	402	(2,882)	(402)
Vesting of performance share units, net 529,213 shares in 2019	(8,248)	1,136	(8,235)	(1,149)
Treasury shares repurchased, 1,321,072 shares and 1,766,826 shares in 2018 and 2019 respectively	(31,838)		(31,838)
Amortization of unearned stock-based compensation, net of forfeitures	11,569			11,569
Balances at Dec. 31, 2019	$ 789,659	$ 143,400	$ (838,893)	$ 200,595	$ 1,824,100	$ (587,622)	$ 48,079