Fair Value Measurements (Details - Significant unobservable quantitative inputs and Investments classified as Level 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Real estate fund investments
Unobservable Quantitative Input [Abstract]
Beginning balance	$ 524,150	$ 565,976	$ 574,761	$ 513,973	$ 513,973
Purchases	0	11	0	95,011
Sales/Dispositions/distributions	0	(8,029)	(71,888)	(91,450)
Net unrealized (losses) gains	(4,764)	(2,544)	16,091	37,001
Net realized gains (losses)	0	(907)	422	1,405
Other, net	0	907	0	(526)
Ending balance	519,386	555,414	$ 519,386	555,414	$ 574,761
Real estate fund investments | Minimum
Unobservable Quantitative Input [Abstract]
Discount rates			12.00%		12.00%
Capitalization rate			4.70%		4.80%
Real estate fund investments | Maximum
Unobservable Quantitative Input [Abstract]
Discount rates			14.90%		14.90%
Capitalization rate			5.80%		6.10%
Real estate fund investments | Weighted Average
Unobservable Quantitative Input [Abstract]
Discount rates			13.70%		13.60%
Capitalization rate			5.40%		5.50%
Deferred Compensation Plan Assets
Unobservable Quantitative Input [Abstract]
Beginning balance	60,140	67,668	$ 59,186	63,315	$ 63,315
Purchases	1,251	2,153	3,523	8,384
Sales/Dispositions/distributions	(3,737)	(171)	(5,888)	(5,264)
Realized and unrealized (losses) gain	(1,055)	(1,466)	(743)	1,256
Other, net	316	24	837	517
Ending balance	$ 56,915	$ 68,208	$ 56,915	$ 68,208	$ 59,186