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	34,439	0	0	0	34,439	0	0
Other comprehensive income/ (loss), net of tax	14,154	0	0	0	0	14,154	0
Dividends paid to common shareholders	(16,602)	0	0	0	(16,602)	0	0
Dividends paid to preferred shareholders	(1,738)	0	0	0	(1,738)	0	0
Net Change in Noncontrolling Interests	(14)	0	0	0	0	0	(14)
Stock Repurchased During Period, Value	(4,495)	0	(399)	(4,096)	0	0	0
Net proceeds from issuance of [Abstract]
Net proceeds from issuance of common stock	738	0	76	662	0	0	0
Issuance of shares through incentive stock grants, net of shares forfeited, canceled, or withheld for employee taxes, value	(738)	0	221	(959)	0	0	0
Amortization of stock compensation and employee stock purchase plan	372	0	0	372	0	0	0
Stock options exercised	529	0	71	458	0	0	0
Tax benefit/ (deficiency) from certain stock compensation awards	(749)	0	0	(749)	0	0	0
Other equity adjustments	1,631	0	0	1,631	0	0	0
Ending Balance at Jun. 30, 2016	774,140	47,753	83,380	597,989	28,985	12,654	3,379
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	39,068	0	0	0	39,068	0	0
Other comprehensive income/ (loss), net of tax	6,510	0	0	0	0	6,510	0
Dividends paid to common shareholders	(18,452)	0	0	0	(18,452)	0	0
Dividends paid to preferred shareholders	(1,738)	0	0	0	(1,738)	0	0
Net Change in Noncontrolling Interests	214	0	0	0	0	0	214
Net proceeds from issuance of [Abstract]
Net proceeds from issuance of common stock	721	0	73	648	0	0	0
Issuance of shares through incentive stock grants, net of shares forfeited, canceled, or withheld for employee taxes, value	(969)	0	(150)	(819)	0	0	0
Exercise of warrants	1,877	0	261	1,616	0	0	0
Amortization of stock compensation and employee stock purchase plan	4,137	0	0	4,137	0	0	0
Stock options exercised	804	0	99	705	0	0	0
Other equity adjustments	(1,234)	0	0	(1,234)	0	0	0
Ending Balance at Jun. 30, 2017	$ 799,419	$ 47,753	$ 84,015	$ 602,507	$ 66,807	$ (6,038)	$ 4,375