Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Cash Flows [Abstract]
Net cash provided by operating activities	$ 206,443	$ 121,443
Cash flows from investing activities:
Sale of investment securities	23,066	81,235
Maturities of investment securities	94,858	4,343
Purchase of investment securities	(120,362)	(90,106)
Proceeds from sale or liquidation of long-term investments	966	1,000
Purchase of long-term investments	(26,500)	(50)
Investments in real estate ventures	(20,830)	(23,358)
Distributions from investments in real estate ventures	23,338	23,041
Increase in cash surrender value of life insurance policies	(831)	(451)
(Increase) decrease in restricted assets	(3,541)	8,615
Issuance of notes receivable	(1,633)	0
Proceeds from sale of fixed assets	75	45
Capital expenditures	(15,258)	(19,157)
Repayments of notes receivable	0	4,410
Acquisition of a business	(6,569)	0
Pay downs of investment securities	2,153	7,842
Investments in real estate, net	(357)	(130)
Net cash used in investing activities	(51,425)	(2,721)
Cash flows from financing activities:
Proceeds from issuance of debt	850,021	243,620
Deferred financing costs	(19,200)	(6,600)
Repayments of debt	(836,600)	(4,698)
Borrowings under revolver	121,521	104,826
Repayments on revolver	(152,870)	(94,644)
Dividends and distributions on common stock	(158,425)	(147,270)
Contributions from non-controlling interest	0	248
Distributions to non-controlling interest	(165)	(9,508)
Proceeds from issuance of Vector common stock	43,230	0
Proceeds from exercise of Vector options	0	398
Tax benefit of options exercised	0	412
Net cash (used in) provided by financing activities	(152,488)	86,784
Net increase in cash and cash equivalents	2,530	205,506
Cash and cash equivalents, beginning of period	393,530	240,368
Cash and cash equivalents, end of period	$ 396,060	$ 445,874