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)		(1,982)						(1,700)	(282)
Other comprehensive income (loss)		(1,288)	[1]				(1,288)
Loss on remeasurement if equity investment		(1,150)
Cash received from noncontrolling interest		14,700							14,700
Adoption of accounting standard, net of income tax		(8,441)						(8,441)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax		1,532			(2,632)	4,164
Dividends declared per common share		(4,663)						(4,663)
Restricted share award dividend equivalents		0				120		(120)
Ending Balance at Mar. 31, 2018		822,757		96	221,990	(36,028)	(3,988)	618,572	22,115
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)		(14,148)						(13,993)	(155)
Other comprehensive income (loss)	[1]	8,861
Other comprehensive income (loss)		(2,770)					(2,770)
Loss on remeasurement if equity investment		11,631					11,631
Loss on remeasurement if equity investment		12,609
Cash received from noncontrolling interest		4,715							4,715
Adoption of accounting standard, net of income tax		(711)						(711)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax		5,188			(22,756)	27,944
Dividends declared per common share		(5,529)						(5,529)
Shares issued for acquisition		123,146		41	123,105
Restricted share award dividend equivalents		0			8	140		(148)
Ending Balance at Mar. 31, 2019		$ 998,286		$ 137	$ 324,753	$ (7,216)	$ 2,474	$ 627,136	$ 51,002

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