Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Balance at at Dec. 31, 2013	$ 344,696	$ 13,196	$ 99,038	$ 258,285	$ (34,700)	$ 8,877
Net income	58,297	0	0	56,492	0	1,805
Amounts reported in other comprehensive income (loss)	(19,943)	0	0	0	(19,706)	(237)
Repurchases of common stock	0	0	0	0	0	0
Dividends common stock	(15,253)	0	0	(15,253)	0	0
Distributions to noncontrolling affiliate shareholders	(1,806)	0	0	0	0	(1,806)
Acqusition of noncontrolling interests, net	(7,422)	0	(6,443)	0	0	(979)
Disposition of noncontrolling interest	0	0	0	0	0	0
Shares issued upon exercise of stock options and other	388	19	369	0	0	0
Shares issued for employee stock purchase plan	416	6	410	0	0	0
Equity based compensation plans	5,309	80	5,229	0	0	0
Excess tax benefit from stock option exercises	453	0	453	0	0	0
Balance at at Dec. 31, 2014	365,135	13,301	99,056	299,524	(54,406)	7,660
Net income	52,706	0	0	51,180	0	1,526
Amounts reported in other comprehensive income (loss)	(19,547)	0	0	0	(18,910)	(637)
Repurchases of common stock	(7,276)	(87)	0	(7,189)	0	0
Dividends common stock	(16,775)	0	0	(16,775)	0	0
Acqusition of noncontrolling interests, net	0	0	0	0	0	0
Disposition of noncontrolling interest	(351)	0	0	0	0	(351)
Shares issued upon exercise of stock options and other	619	17	602	0	0	0
Shares issued for employee stock purchase plan	429	6	423	0	0	0
Equity based compensation plans	5,919	51	5,868	0	0	0
Excess tax benefit from stock option exercises	384	0	384	0	0	0
Balance at at Dec. 31, 2015	381,243	13,288	106,333	326,740	(73,316)	8,198
Net income	63,039	0	0	61,403	0	1,636
Amounts reported in other comprehensive income (loss)	(14,152)	0	0	0	(14,091)	(61)
Repurchases of common stock	(5,859)	(84)	0	(5,775)	0	0
Dividends common stock	(17,954)	0	0	(17,954)	0	0
Acquisition of Noncontrolling Interests	73	0	0	0	0	73
Shares issued upon exercise of stock options and other	(1,302)	11	(1,313)	0	0	0
Shares issued for employee stock purchase plan	491	6	485	0	0	0
Equity based compensation plans	6,349	57	6,292	0	0	0
Excess tax benefit from stock option exercises	678	0	678	0	0	0
Balance at at Dec. 31, 2016	$ 412,606	$ 13,278	$ 112,475	$ 364,414	$ (87,407)	$ 9,846