Consolidated Statement of Shareholders' 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, 2013	$ 633,688	$ 47,753	$ 79,838	$ 616,334	$ (106,211)	$ (4,197)	$ 171
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income attributable to the Company	68,815	0	0	0	68,815	0	0
Other comprehensive income/ (loss), net	3,500	0	0	0	0	3,500	0
Dividends paid to common shareholders: $0.32 per share	(25,829)	0	0	(25,829)	0	0	0
Dividends paid to preferred shareholders	(3,475)	0	0	(3,475)	0	0	0
Issuance of noncontrolling interests	215	0	0	0	0	0	215
Net proceeds from issuance of:
Stock Issued During Period, Value, Employee Stock Purchase Plan	22,264	0	1,801	20,463	0	0	0
Stock Issued under Equity Plans, net of shares forfeited, canceled, or withheld for employee taxes, value	(1,609)	0	1,091	(2,700)	0	0	0
Amortization of stock compensation and employee stock purchase plan	6,239	0	0	6,239	0	0	0
Stock options exercised	1,807	0	232	1,575	0	0	0
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	1,294	0	0	1,294	0	0	0
Other equity adjustments	(2,998)	0	0	(2,998)	0	0	0
Ending Balance at Dec. 31, 2014	703,911	47,753	82,962	610,903	(37,396)	(697)	386
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income attributable to the Company	64,925	0	0	0	64,925	0	0
Other comprehensive income/ (loss), net	(803)	0	0	0	0	(803)	0
Dividends paid to common shareholders: $0.32 per share	(29,608)	0	0	(16,703)	(12,905)	0	0
Dividends paid to preferred shareholders	(3,475)	0	0	(1,737)	(1,738)	0	0
Issuance of noncontrolling interests	3,007	0	0	0	0	0	3,007
Net proceeds from issuance of:
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,575	0	138	1,437	0	0	0
Stock Issued under Equity Plans, net of shares forfeited, canceled, or withheld for employee taxes, value	(2,090)	0	161	(2,251)	0	0	0
Amortization of stock compensation and employee stock purchase plan	9,820	0	0	9,820	0	0	0
Stock options exercised	1,206	0	150	1,056	0	0	0
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	(1,262)	0	0	(1,262)	0	0	0
Other equity adjustments	(593)	0	0	(593)	0	0	0
Ending Balance at Dec. 31, 2015	746,613	47,753	83,411	600,670	12,886	(1,500)	3,393
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income attributable to the Company	71,628	0	0	0	71,628	0	0
Other comprehensive income/ (loss), net	(11,048)	0	0	0	0	(11,048)	0
Dividends paid to common shareholders: $0.32 per share	(33,110)	0	0	0	(33,110)	0	0
Dividends paid to preferred shareholders	(3,475)	0	0	0	(3,475)	0	0
Issuance of noncontrolling interests	768	0	0	0	0	0	768
Stock Repurchased During Period, Value	9,323	0	786	8,537	0	0	0
Net proceeds from issuance of:
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,579	0	166	1,413	0	0	0
Stock Issued under Equity Plans, net of shares forfeited, canceled, or withheld for employee taxes, value	(737)	0	193	(930)	0	0	0
Adjustments to Additional Paid in Capital, Warrant Issued	0	0	517	(517)	0	0	0
Amortization of stock compensation and employee stock purchase plan	4,112	0	0	4,112	0	0	0
Stock options exercised	1,725	0	231	1,494	0	0	0
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	(620)	0	0	(620)	0	0	0
Other equity adjustments	369	0	0	369	0	0	0
Ending Balance at Dec. 31, 2016	$ 768,481	$ 47,753	$ 83,732	$ 597,454	$ 47,929	$ (12,548)	$ 4,161