Earnings Per Share (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Basic earnings per share - Numerator:
Net income from continuing operations									$ 80,390,000	$ 81,869,000	$ 40,189,000
Net income attributable to noncontrolling interests	$ 97,000	$ 96,000	$ 69,000	$ 100,000	$ 545,000	$ 924,000	$ 968,000	$ 1,050,000	362,000	3,487,000	4,468,000
Net income from continuing operations attributable to the Company									80,028,000	78,382,000	35,721,000
Decrease/(increase) in noncontrolling interests’ redemption values									1,143,000	2,303,000	(1,412,000)
Dividends on preferred stock									0	(3,985,000)	(3,475,000)
Total adjustments to income attributable to common shareholders									1,143,000	(1,682,000)	(4,887,000)
Net income from continuing operations attributable to common shareholders, treasury stock method									81,171,000	76,700,000	30,834,000
Net income from discontinued operations					$ 306,000	$ 0	$ (2,000)	$ 1,698,000	0	2,002,000	4,870,000
Net income attributable to common shareholders for earnings per share calculation									$ 81,171,000	$ 78,702,000	$ 35,704,000
Basic earnings per share - Denominator:
Weighted average basic common shares outstanding (in shares)									83,430,740	83,596,685	82,430,633
Per share data - Basic earnings per share from:
From continuing operations: (in dollars per share)									$ 0.97	$ 0.92	$ 0.37
From discontinued operations: (in dollars per share)									0	0.02	0.06
Total attributable to common shareholders: (in dollars per share)	$ 0.26	$ 0.24	$ 0.22	$ 0.25	$ 0.43	$ 0.20	$ 0.03	$ 0.27	$ 0.97	$ 0.94	$ 0.43
Diluted earnings per share - Numerator:
Net income from continuing operations attributable to common shareholders, after assumed dilution									$ 81,171,000	$ 76,700,000	$ 30,834,000
Net income from discontinued operations					$ 306,000	$ 0	$ (2,000)	$ 1,698,000	0	2,002,000	4,870,000
Net income attributable to common shareholders for basic earnings per share calculation									$ 81,171,000	$ 78,702,000	$ 35,704,000
Diluted Earnings Per Share, Denominator [Abstract]
Weighted average basic common shares outstanding (in shares)									83,430,740	83,596,685	82,430,633
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)									490,052	1,002,764	1,313,953
Warrants to purchase common stock (in shares)									0	731,865	1,057,979
Dilutive common shares (in shares)									490,052	1,734,629	2,371,932
Weighted average diluted common shares outstanding (in shares)									83,920,792	85,331,314	84,802,565
Per share data - Diluted earnings per share from:
Continuing operations (in dollars per share)									$ 0.97	$ 0.90	$ 0.36
Discontinued operations (in dollars per share)									0	0.02	0.06
Total attributable to common shareholders: (in dollars per share)	$ 0.26	$ 0.24	$ 0.22	$ 0.25	$ 0.42	$ 0.20	$ 0.03	$ 0.27	0.97	0.92	0.42
Dividends per share declared and paid on common stock (in dollars per share)									$ 0.48	$ 0.48	$ 0.44
Preferred stock dividend rate									6.95%	6.95%
Shares excluded due to anti-dilution (treasury stock method) (in shares)									1,000	52,000	1,000
Shares excluded due to exercise price exceeding the average market price of common shares during the period (in shares)									853,000	209,000	67,000
Holding Company and Eliminations
Basic earnings per share - Numerator:
Net income from continuing operations									$ (4,051,000)	$ 4,952,000	$ (15,663,000)
Net income attributable to noncontrolling interests									362,000	3,487,000	4,468,000
Net income from discontinued operations									0	2,002,000	4,870,000
Diluted earnings per share - Numerator:
Net income from discontinued operations									$ 0	$ 2,002,000	$ 4,870,000
Market-based Stock Options
Per share data - Diluted earnings per share from:
Shares excluded due to anti-dilution (treasury stock method) (in shares)									0	51,000	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)									853,000	209,000	67,000
Series D Preferred Stock
Per share data - Diluted earnings per share from:
Preferred stock dividend rate									6.95%