Equity and Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Beginning Balance	$ 378,526	$ 364,710	$ 365,135	$ 344,696
Net Income	14,835	16,119	40,854	45,370
Amounts reported in other comprehensive income (loss)	(11,361)	(10,072)	(17,820)	(6,760)
Repurchases of common stock	(3,359)	0	(4,989)	0
Dividends, Common Stock	(4,256)	(3,981)	(12,525)	(11,262)
Distributions to Noncontrolling Affiliate Shareholders	0	(1,149)	0	(1,806)
Acquisition of Noncontrolling Interest	0	155	0	(7,422)
Disposition of Noncontrolling Interest	0	0	(351)	0
Share Issuance and Equity-Based Compensation Plans	1,744	1,066	5,447	3,765
Excess Tax Benefit From Stock Option Exercises	22	163	400	430
Ending Balance	376,151	367,011	376,151	367,011
Common Stock [Member]
Beginning Balance	13,337	13,242	13,301	13,196
Net Income	0	0	0	0
Amounts reported in other comprehensive income (loss)	0	0	0	0
Repurchases of common stock	(40)	0	(59)	0
Dividends, Common Stock	0	0	0	0
Distributions to Noncontrolling Affiliate Shareholders	0	0	0	0
Acquisition of Noncontrolling Interest	0	0	0	0
Disposition of Noncontrolling Interest	0	0	0	0
Share Issuance and Equity-Based Compensation Plans	9	27	64	73
Excess Tax Benefit From Stock Option Exercises	0	0	0	0
Ending Balance	13,306	13,269	13,306	13,269
Additional Paid-in Capital [Member]
Beginning Balance	103,082	95,508	99,056	99,038
Net Income	0	0	0	0
Amounts reported in other comprehensive income (loss)	0	0	0	0
Repurchases of common stock	0	0	0	0
Dividends, Common Stock	0	0	0	0
Distributions to Noncontrolling Affiliate Shareholders	0	0	0	0
Acquisition of Noncontrolling Interest	0	7	0	(6,443)
Disposition of Noncontrolling Interest	0	0	0	0
Share Issuance and Equity-Based Compensation Plans	1,735	1,039	5,383	3,692
Excess Tax Benefit From Stock Option Exercises	22	163	400	430
Ending Balance	104,839	96,717	104,839	96,717
Retained Earnings [Member]
Beginning Balance	315,060	279,161	299,524	258,285
Net Income	14,371	15,696	39,787	43,853
Amounts reported in other comprehensive income (loss)	0	0	0	0
Repurchases of common stock	(3,319)	0	(4,930)	0
Dividends, Common Stock	(4,256)	(3,981)	(12,525)	(11,262)
Distributions to Noncontrolling Affiliate Shareholders	0	0	0	0
Acquisition of Noncontrolling Interest	0	0	0	0
Disposition of Noncontrolling Interest	0	0	0	0
Share Issuance and Equity-Based Compensation Plans	0	0	0	0
Excess Tax Benefit From Stock Option Exercises	0	0	0	0
Ending Balance	321,856	290,876	321,856	290,876
Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance	(60,771)	(31,587)	(54,406)	(34,700)
Net Income	0	0	0	0
Amounts reported in other comprehensive income (loss)	(10,994)	(9,826)	(17,359)	(6,713)
Repurchases of common stock	0	0	0	0
Dividends, Common Stock	0	0	0	0
Distributions to Noncontrolling Affiliate Shareholders	0	0	0	0
Acquisition of Noncontrolling Interest	0	0	0	0
Disposition of Noncontrolling Interest	0	0	0	0
Share Issuance and Equity-Based Compensation Plans	0	0	0	0
Excess Tax Benefit From Stock Option Exercises	0	0	0	0
Ending Balance	(71,765)	(41,413)	(71,765)	(41,413)
Noncontrolling Interest [Member]
Beginning Balance	7,818	8,386	7,660	8,877
Net Income	464	423	1,067	1,517
Amounts reported in other comprehensive income (loss)	(367)	(246)	(461)	(47)
Repurchases of common stock	0	0	0	0
Dividends, Common Stock	0	0	0	0
Distributions to Noncontrolling Affiliate Shareholders	0	(1,149)	0	(1,806)
Acquisition of Noncontrolling Interest	0	148	0	(979)
Disposition of Noncontrolling Interest	0	0	(351)	0
Share Issuance and Equity-Based Compensation Plans	0	0	0	0
Excess Tax Benefit From Stock Option Exercises	0	0	0	0
Ending Balance	$ 7,915	$ 7,562	$ 7,915	$ 7,562