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, 2014	$ 703,911	$ 47,753	$ 82,962	$ 610,903	$ (37,396)	$ (697)	$ 386
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the Company	36,393	0	0	0	36,393	0	0
Other comprehensive income/ (loss), net of tax	(1,828)	0	0	0	0	(1,828)	0
Dividends paid to common shareholders	(14,882)	0	0	(14,882)	0	0	0
Dividends paid to preferred shareholders	(1,738)	0	0	(1,738)	0	0	0
Net Change in Noncontrolling Interests	2,510	0	0	0	0	0	2,510
Net proceeds from issuance of [Abstract]
Net proceeds from issuance of common stock	679	0	59	620	0	0	0
Issuance of shares through incentive stock grants, net of shares forfeited, canceled, or withheld for employee taxes, value	(1,248)	0	390	(1,638)	0	0	0
Amortization of stock compensation and employee stock purchase plan	4,399	0	0	4,399	0	0	0
Stock options exercised	1,025	0	129	896	0	0	0
Tax benefit/ (deficiency) from certain stock compensation awards	95	0	0	95	0	0	0
Other equity adjustments	(1,231)	0	0	(1,231)	0	0	0
Ending Balance at Jun. 30, 2015	728,085	47,753	83,540	597,424	(1,003)	(2,525)	2,896
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