CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock Issued	Common Stock Treasury	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests
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
Net income	22,537				20,697		1,840
Sale of subsidiary shares to noncontrolling interest	876						876
Total other comprehensive income (loss), net of deferred income taxes of $(5,267) and $1,729 for the three months ended March 31, 2020 and 2019, respectively	4,531					4,111	420
Stock appreciation rights exercised, net	(8)	2	(8)	(2)
Vesting of restricted stock units and other stock grants, net	(1,456)	198	(1,456)	(198)
Vesting of performance share units, net	(8,248)	1,136	(8,235)	(1,149)
Amortization of unearned portion of stock-based compensation, net of forfeitures	3,664			3,664
Balances at Mar. 31, 2019	335,272	143,178	(805,520)	192,912	1,340,878	(584,425)	48,249
Balances at Dec. 31, 2019	789,659	143,400	(838,893)	200,595	1,824,100	(587,622)	48,079
Increase (Decrease) in Stockholders' Equity
Net income	1,227				141		1,086
Total other comprehensive income (loss), net of deferred income taxes of $(5,267) and $1,729 for the three months ended March 31, 2020 and 2019, respectively	(30,002)					(28,854)	(1,148)
Vesting of restricted stock units and other stock grants, net	(889)	230	(889)	(230)
Vesting of performance share units, net	(3,205)	589	(3,205)	(589)
Amortization of unearned portion of stock-based compensation, net of forfeitures	2,080			2,080
Balances at Mar. 31, 2020	$ 758,870	$ 144,219	$ (842,987)	$ 201,856	$ 1,824,241	$ (616,476)	$ 48,017