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
Cash dividends declared:
Sale of subsidiary shares to noncontrolling interest		477						477
Total other comprehensive income (loss), net of deferred income taxes of $(2,118) and $(689); and $(1,569) and $(3,909); and $1,729 and $467 for the three months ended September 30, 2019 and 2018, June 30, 2019 and 2018 and the three months ended March 31, 2019 and 2018, respectively		6,163					4,885	1,278
Stock appreciation rights exercised, net		(26)	5	(26)	(5)
Vesting of restricted stock units and other stock grants, net		(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
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		96,939
Cash dividends declared:
Total other comprehensive income (loss), net of deferred income taxes of $(2,118) and $(689); and $(1,569) and $(3,909); and $1,729 and $467 for the three months ended September 30, 2019 and 2018, June 30, 2019 and 2018 and the three months ended March 31, 2019 and 2018, respectively		(9,801)
Balances at Sep. 30, 2018		304,391	141,837	(765,765)	187,930	1,252,840	(555,291)	42,840
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
Net income		42,711				40,489		2,222
Cash dividends declared:
Noncontrolling interests		(5,521)						(5,521)
Total other comprehensive income (loss), net of deferred income taxes of $(2,118) and $(689); and $(1,569) and $(3,909); and $1,729 and $467 for the three months ended September 30, 2019 and 2018, June 30, 2019 and 2018 and the three months ended March 31, 2019 and 2018, respectively		(17,190)					(14,672)	(2,518)
Stock appreciation rights exercised, net		(175)	34	(175)	(34)
Vesting of restricted stock units and other stock grants, net		(2,732)	492	(2,732)	(492)
Amortization of unearned portion of stock-based compensation, net of forfeitures		2,728			2,728
Balances at Jun. 30, 2018		266,153	141,812	(765,695)	185,512	1,219,992	(557,889)	42,421
Increase (Decrease) in Stockholders' Equity
Adoption of new accounting standards (See Note 2)		(13)				(13)
Net income		34,651				32,847		1,804
Cash dividends declared:
Noncontrolling interests		(13)						(13)
Total other comprehensive income (loss), net of deferred income taxes of $(2,118) and $(689); and $(1,569) and $(3,909); and $1,729 and $467 for the three months ended September 30, 2019 and 2018, June 30, 2019 and 2018 and the three months ended March 31, 2019 and 2018, respectively		1,226					2,598	(1,372)
Stock appreciation rights exercised, net		(72)	10	(72)	(10)
Vesting of restricted stock units and other stock grants, net		2	15	2	(15)
Amortization of unearned portion of stock-based compensation, net of forfeitures		2,443			2,443
Balances at Sep. 30, 2018		304,391	141,837	(765,765)	187,930	1,252,840	(555,291)	42,840
Increase (Decrease) in Stockholders' Equity
Adoption of new accounting standards (See Note 2)		1				1
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
Cash dividends declared:
Sale of subsidiary shares to noncontrolling interest		876						876
Total other comprehensive income (loss), net of deferred income taxes of $(2,118) and $(689); and $(1,569) and $(3,909); and $1,729 and $467 for the three months ended September 30, 2019 and 2018, June 30, 2019 and 2018 and the three months ended March 31, 2019 and 2018, 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, 2018		313,376	141,842	(795,821)	190,597	1,298,752	(567,107)	45,113
Increase (Decrease) in Stockholders' Equity
Net income		471,323
Cash dividends declared:
Total other comprehensive income (loss), net of deferred income taxes of $(2,118) and $(689); and $(1,569) and $(3,909); and $1,729 and $467 for the three months ended September 30, 2019 and 2018, June 30, 2019 and 2018 and the three months ended March 31, 2019 and 2018, respectively		(1,091)
Balances at Sep. 30, 2019		751,260	143,396	(832,775)	198,007	1,784,871	(587,759)	45,520
Balances at Mar. 31, 2019		335,272	143,178	(805,520)	192,912	1,340,878	(584,425)	48,249
Increase (Decrease) in Stockholders' Equity
Net income		10,929				8,642		2,287
Cash dividends declared:
Noncontrolling interests		(4,690)						(4,690)
Total other comprehensive income (loss), net of deferred income taxes of $(2,118) and $(689); and $(1,569) and $(3,909); and $1,729 and $467 for the three months ended September 30, 2019 and 2018, June 30, 2019 and 2018 and the three months ended March 31, 2019 and 2018, respectively		3,598					4,196	(598)
Contribution receivable from noncontrolling interest	[1]	3,150						3,150
Stock appreciation rights exercised, net		(108)	18	(108)	(18)
Vesting of restricted stock units and other stock grants, net		(1,375)	198	(1,375)	(198)
Amortization of unearned portion of stock-based compensation, net of forfeitures		2,338			2,338
Balances at Jun. 30, 2019		349,114	143,394	(807,003)	195,034	1,349,520	(580,229)	48,398
Increase (Decrease) in Stockholders' Equity
Net income		437,857				435,351		2,506
Cash dividends declared:
Total other comprehensive income (loss), net of deferred income taxes of $(2,118) and $(689); and $(1,569) and $(3,909); and $1,729 and $467 for the three months ended September 30, 2019 and 2018, June 30, 2019 and 2018 and the three months ended March 31, 2019 and 2018, respectively		(9,220)					(7,530)	(1,690)
Stock appreciation rights exercised, net		(1)		(1)
Vesting of restricted stock units and other stock grants, net		(19)	2	(19)	(2)
Treasury Stock, Value, Acquired, Cost Method		(25,752)		25,752
Amortization of unearned portion of stock-based compensation, net of forfeitures		2,975			2,975
Balances at Sep. 30, 2019		$ 751,260	$ 143,396	$ (832,775)	$ 198,007	$ 1,784,871	$ (587,759)	$ 45,520

[1] Cash contribution was received during July 2019.