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, 2017	$ 215,165	$ 141,110	$ (762,079)	$ 180,201	$ 1,157,801	$ (546,582)	$ 44,714
Increase (Decrease) in Stockholders' Equity
Net income	19,577				17,808		1,769
Sale of subsidiary shares to noncontrolling interest	477						477
Total other comprehensive income (loss), net of deferred income taxes of $1,729 and $467 in 2019 and 2018, respectively	6,163					4,885	1,278
Stock Appreciation Rights exercised, net 927 shares and 2,560 shares in 2019 and 2018, respectively	(26)	5	(26)	(5)
Vesting of restricted stock units and other stock grants, net 94,229 shares and 102,695 shares in 2019 and 2018, respectively	(683)	171	(683)	(171)
Amortization of unearned portion of stock-based compensation, net of forfeitures	3,285			3,285
Balances at Mar. 31, 2018	246,345	141,286	(762,788)	183,310	1,179,516	(543,217)	48,238
Increase (Decrease) in Stockholders' Equity
Adoption of new accounting standards (See Note 2)	0					(21,429)
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 $1,729 and $467 in 2019 and 2018, respectively	4,531					4,111	420
Stock Appreciation Rights exercised, net 927 shares and 2,560 shares in 2019 and 2018, respectively	(8)	2	(8)	(2)
Vesting of restricted stock units and other stock grants, net 94,229 shares and 102,695 shares in 2019 and 2018, respectively	(1,456)	198	(1,456)	(198)
Vesting of performance share unites, net 529,213 shares in 2019	(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