Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic earnings per share - Numerator:
Net income from continuing operations									$ 81,869	$ 40,189	$ 70,244
Net income attributable to noncontrolling interests	$ 545	$ 924	$ 968	$ 1,050	$ 1,278	$ 1,074	$ 1,150	$ 966	3,487	4,468	4,157
Net income from continuing operations attributable to the Company									78,382	35,721	66,087
Decrease/ (increase) in noncontrolling interests’ redemption values									2,303	(1,412)	(588)
Dividends on preferred stock									(3,985)	(3,475)	(3,475)
Total adjustments to income attributable to common shareholders									(1,682)	(4,887)	(4,063)
Net income from continuing operations attributable to common shareholders, treasury stock method									76,700	30,834	62,024
Net income from discontinued operations	$ 306	$ 0	$ (2)	$ 1,698	$ 989	$ 1,186	$ 1,063	$ 1,632	2,002	4,870	5,541
Net income attributable to common shareholders for earnings per share calculation									$ 78,702	$ 35,704	$ 67,565
Basic earnings per share - Denominator:
Weighted average basic common shares outstanding (in shares)									83,596,685	82,430,633	81,264,273
Per share data - Basic earnings per share from:
From continuing operations: (in dollars per share)									$ 0.92	$ 0.37	$ 0.76
From discontinued operations: (in dollars per share)									0.02	0.06	0.07
Total attributable to common shareholders: (in dollars per share)	$ 0.43	$ 0.20	$ 0.03	$ 0.27	$ (0.24)	$ 0.23	$ 0.28	$ 0.18	$ 0.94	$ 0.43	$ 0.83
Diluted earnings per share - Numerator:
Net income from discontinued operations	$ 306	$ 0	$ (2)	$ 1,698	$ 989	$ 1,186	$ 1,063	$ 1,632	$ 2,002	$ 4,870	$ 5,541
Net income attributable to common shareholders for basic earnings per share calculation									$ 78,702	$ 35,704	$ 67,565
Diluted Earnings Per Share, Denominator [Abstract]
Weighted average basic common shares outstanding (in shares)									83,596,685	82,430,633	81,264,273
Dilutive effect of:
Stock options, performance-based and time-based restricted stock, and performance-based and time-based restricted stock units, and other dilutive securities (in shares)									1,002,764	1,313,953	1,002,153
Warrants to purchase common stock (in shares)									731,865	1,057,979	942,700
Dilutive common shares (in shares)									1,734,629	2,371,932	1,944,853
Weighted average diluted common shares outstanding (in shares)									85,331,314	84,802,565	83,209,126
Per share data - Diluted earnings per share from:
Continuing operations (in dollars per share)									$ 0.90	$ 0.36	$ 0.74
Discontinued operations (in dollars per share)									0.02	0.06	0.07
Total attributable to common shareholders: (in dollars per share)	$ 0.42	$ 0.20	$ 0.03	$ 0.27	$ (0.24)	$ 0.22	$ 0.27	$ 0.17	0.92	0.42	0.81
Dividends per share declared and paid on common stock (in dollars per share)									$ 0.48	$ 0.44	$ 0.4
Preferred stock dividend rate									6.95%	6.95%
Shares excluded due to anti-dilution (treasury stock method) (in shares)									52,000	1,000	1,000
Shares excluded due to exercise price exceeding the average market price of common shares during the period (in shares)									209,000	67,000	270,000
Market-based Stock Options
Per share data - Diluted earnings per share from:
Shares excluded due to anti-dilution (treasury stock method) (in shares)									51,000	0	0
Convertible trust preferred securities
Per share data - Diluted earnings per share from:
Shares excluded due to anti-dilution (treasury stock method) (in shares)									1,000	1,000	1,000
Options, restricted stock, or other dilutive securities
Per share data - Diluted earnings per share from:
Shares excluded due to exercise price exceeding the average market price of common shares during the period (in shares)									209,000	67,000	270,000
Series D Preferred Stock
Basic earnings per share - Numerator:
Dividends on preferred stock									$ (2,200)
Per share data - Diluted earnings per share from:
Preferred stock dividend rate										6.95%