Equity and Noncontrolling Interest (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Beginning Balance	$ 312,357	$ 280,745	$ 289,676	$ 261,357
Net Income	13,305	11,623	44,171	36,473
Amounts reported in other comprehensive income (loss)	1,759	2,539	(2,602)	836
Dividends, Common Stock	(3,298)	(3,214)	(9,810)	(9,516)
Dividends Paid to Noncontrolling Interest	(30)	0	(30)	(30)
Share Issuance and Equity-Based Compensation Plans	387	973	2,623	2,126
Excess Tax Benefit From Stock Option Exercises	363	744	815	2,164
Ending Balance	324,843	293,410	324,843	293,410
Common Stock Member
Beginning Balance	13,168	13,011	13,095	12,912
Net Income	0	0	0	0
Amounts reported in other comprehensive income (loss)	0	0	0	0
Dividends, Common Stock	0	0	0	0
Dividends Paid to Noncontrolling Interest	0	0	0	0
Share Issuance and Equity-Based Compensation Plans	19	71	92	170
Excess Tax Benefit From Stock Option Exercises	0	0	0	0
Ending Balance	13,187	13,082	13,187	13,082
Additional Paid-in Capital [Member]
Beginning Balance	97,085	92,199	94,470	89,725
Net Income	0	0	0	0
Amounts reported in other comprehensive income (loss)	0	0	0	0
Dividends, Common Stock	0	0	0	0
Dividends Paid to Noncontrolling Interest	0	0	0	0
Share Issuance and Equity-Based Compensation Plans	368	902	2,531	1,956
Excess Tax Benefit From Stock Option Exercises	363	744	815	2,164
Ending Balance	97,816	93,845	97,816	93,845
Retained Earnings [Member]
Beginning Balance	238,580	197,881	215,390	180,710
Net Income	12,551	10,925	42,253	34,398
Amounts reported in other comprehensive income (loss)	0	0	0	0
Dividends, Common Stock	(3,298)	(3,214)	(9,810)	(9,516)
Dividends Paid to 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	247,833	205,592	247,833	205,592
Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance	(45,252)	(30,536)	(41,855)	(28,967)
Net Income	0	0	0	0
Amounts reported in other comprehensive income (loss)	2,014	2,311	(1,383)	742
Dividends, Common Stock	0	0	0	0
Dividends Paid to 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	(43,238)	(28,225)	(43,238)	(28,225)
Noncontrolling Interest [Member]
Beginning Balance	8,776	8,190	8,576	6,977
Net Income	754	698	1,918	2,075
Amounts reported in other comprehensive income (loss)	(255)	228	(1,219)	94
Dividends, Common Stock	0	0	0	0
Dividends Paid to Noncontrolling Interest	(30)	0	(30)	(30)
Share Issuance and Equity-Based Compensation Plans	0	0	0	0
Excess Tax Benefit From Stock Option Exercises	0	0	0	0
Ending Balance	$ 9,245	$ 9,116	$ 9,245	$ 9,116