Equity and Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Beginning Balance	$ 408,864	$ 412,606
Net Income	12,787	7,614
Amounts reported in other comprehensive income (loss)	6,457	5,966
Dividends, Common Stock	(4,729)	(4,587)
Distributions to Noncontrolling Affiliate Shareholders	(834)	0
Share Issuance and Equity-Based Compensation Plans	218	376
Ending Balance	422,763	421,975
Common Stock [Member]
Beginning Balance	13,308	13,278
Net Income	0	0
Amounts reported in other comprehensive income (loss)	0	0
Dividends, Common Stock	0	0
Distributions to Noncontrolling Affiliate Shareholders	0	0
Share Issuance and Equity-Based Compensation Plans	15	13
Ending Balance	13,323	13,291
Additional Paid-in Capital [Member]
Beginning Balance	93,528	112,475
Net Income	0	0
Amounts reported in other comprehensive income (loss)	0	0
Dividends, Common Stock	0	0
Distributions to Noncontrolling Affiliate Shareholders	0	0
Share Issuance and Equity-Based Compensation Plans	203	363
Ending Balance	93,731	112,838
Retained Earnings [Member]
Beginning Balance	365,182	364,414
Net Income	12,732	6,992
Amounts reported in other comprehensive income (loss)	0	0
Dividends, Common Stock	(4,729)	(4,587)
Distributions to Noncontrolling Affiliate Shareholders	0	0
Share Issuance and Equity-Based Compensation Plans	0	0
Ending Balance	373,185	366,819
Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance	(65,100)	(87,407)
Net Income	0	0
Amounts reported in other comprehensive income (loss)	6,362	5,446
Dividends, Common Stock	0	0
Distributions to Noncontrolling Affiliate Shareholders	0	0
Share Issuance and Equity-Based Compensation Plans	0	0
Ending Balance	(58,738)	(81,961)
Noncontrolling Interest [Member]
Beginning Balance	1,946	9,846
Net Income	55	622
Amounts reported in other comprehensive income (loss)	95	520
Dividends, Common Stock	0	0
Distributions to Noncontrolling Affiliate Shareholders	(834)	0
Share Issuance and Equity-Based Compensation Plans	0	0
Ending Balance	$ 1,262	$ 10,988