Condensed Consolidated Statements of Equity - USD ($) $ in Thousands		Total		Common Shares	Additional Paid-in Capital	Treasury Shares	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Noncontrolling Interests
Beginning Balance at Dec. 31, 2017		$ 822,899		$ 96	$ 224,622	$ (40,312)	$ (2,700)	$ 633,496	$ 7,697
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		17,557						17,732	(175)
Other comprehensive income (loss)		(1,664)	[1]				(1,664)
Cash received from (paid to) noncontrolling interest		21,116			(2,268)				23,384
Adoption of accounting standard, net of income tax of $2,869		(8,441)						(8,441)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax		5,167			14	5,153
Dividends declared per common share		(13,991)						(13,991)
Restricted share award dividend equivalents		0				120		(120)
Ending Balance at Sep. 30, 2018		842,643		96	222,368	(35,039)	(4,364)	628,676	30,906
Beginning Balance at Jun. 30, 2018		846,990		96	223,259	(35,561)	(5,347)	635,438	29,105
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(1,875)						(2,098)	223
Other comprehensive income (loss)		983	[1]				983
Cash received from (paid to) noncontrolling interest		(690)			(2,268)				1,578
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax		1,899			1,377	522
Dividends declared per common share		(4,664)						(4,664)
Ending Balance at Sep. 30, 2018		842,643		96	222,368	(35,039)	(4,364)	628,676	30,906
Beginning Balance at Dec. 31, 2018		876,764		96	224,396	(35,300)	(6,387)	647,517	46,442
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		9,393						11,658	(2,265)
Other comprehensive income (loss)	[1]	(1,233)
Cash received from (paid to) noncontrolling interest		4,879			164				4,715
Other comprehensive income (loss)		(12,719)					(12,719)
Amounts reclassified from accumulated other comprehensive loss		11,486					11,486
Adoption of accounting standard, net of income tax of $2,869		(711)						(711)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax		11,023			(16,452)	27,475
Dividends declared per common share		(16,606)						(16,606)
Stock awards granted due to acquisition		127,841		41	127,800
Restricted share award dividend equivalents		0			8	243		(251)
Ending Balance at Sep. 30, 2019		1,011,350		137	335,916	(7,582)	(7,620)	641,607	48,892
Beginning Balance at Jun. 30, 2019		1,020,639		137	331,186	(6,449)	(6,241)	651,481	50,525
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(5,870)						(4,237)	(1,633)
Other comprehensive income (loss)	[1]	(1,379)
Cash received from (paid to) noncontrolling interest		164			164
Other comprehensive income (loss)		(1,405)					(1,405)
Amounts reclassified from accumulated other comprehensive loss		26					26
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax		3,343			4,566	(1,223)
Dividends declared per common share		(5,547)						(5,547)
Restricted share award dividend equivalents		0				90		(90)
Ending Balance at Sep. 30, 2019		$ 1,011,350		$ 137	$ 335,916	$ (7,582)	$ (7,620)	$ 641,607	$ 48,892

[1] All amounts are net of tax. Amounts in parentheses indicate debits