Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock Including Additional Paid in Capital [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2015	$ 746,613	$ 47,753	$ 83,411	$ 600,670	$ 12,886	$ (1,500)	$ 3,393
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the Company	54,075	0	0	0	54,075	0	0
Other comprehensive income/ (loss), net of tax	11,634	0	0	0	0	11,634	0
Dividends paid to common shareholders	(24,940)	0	0	0	(24,940)	0	0
Dividends paid to preferred shareholders	(2,606)	0	0	0	(2,606)	0	0
Net Change in Noncontrolling Interests	389	0	0	0	0	0	389
Stock Repurchased During Period, Value	(8,020)	0	(684)	(7,336)	0	0	0
Net proceeds from issuance of [Abstract]
Net proceeds from issuance of common stock	1,579	0	166	1,413	0	0	0
Issuance of shares through incentive stock grants, net of shares forfeited, canceled, or withheld for employee taxes, value	(738)	0	201	(939)	0	0	0
Amortization of stock compensation and employee stock purchase plan	2,186	0	0	2,186	0	0	0
Stock options exercised	789	0	101	688	0	0	0
Tax benefit/ (deficiency) from certain stock compensation awards	(728)	0	0	(728)	0	0	0
Other equity adjustments	1,255	0	0	1,255	0	0	0
Ending Balance at Sep. 30, 2016	781,488	47,753	83,195	597,209	39,415	10,134	3,782
Beginning Balance at Dec. 31, 2016	768,481	47,753	83,732	597,454	47,929	(12,548)	4,161
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the Company	58,871	0	0	0	58,871	0	0
Other comprehensive income/ (loss), net of tax	7,725	0	0	0	0	7,725	0
Dividends paid to common shareholders	(27,739)	0	0	0	(27,739)	0	0
Dividends paid to preferred shareholders	(2,606)	0	0	0	(2,606)	0	0
Net Change in Noncontrolling Interests	631	0	0	0	0	0	631
Net proceeds from issuance of [Abstract]
Net proceeds from issuance of common stock	1,601	0	140	1,461	0	0	0
Issuance of shares through incentive stock grants, net of shares forfeited, canceled, or withheld for employee taxes, value	(969)	0	(153)	(816)	0	0	0
Exercise of warrants	1,879	0	261	1,618	0	0	0
Amortization of stock compensation and employee stock purchase plan	6,183	0	0	6,183	0	0	0
Stock options exercised	827	0	102	725	0	0	0
Other equity adjustments	177	0	0	177	0	0	0
Ending Balance at Sep. 30, 2017	$ 815,061	$ 47,753	$ 84,082	$ 606,802	$ 76,455	$ (4,823)	$ 4,792