Condensed Consolidating Financial Information Statements of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	$ 140,018	$ 100,044
Cash flows from investing activities:
Sale of investment securities	161,029	173,046
Maturities of investment securities	2,653	517
Purchase of investment securities	(162,845)	(312,919)
Proceeds from sale or liquidation of long-term investments	182	549
Purchase of long-term investments	(10,000)	(12,000)
Investments in real estate ventures	(43,280)	(29,378)
Purchase of subsidiaries	0	(250)
Distributions from investments in real estate ventures	11,205	5,540
Increase in cash surrender value of life insurance policies	(1,225)	(435)
Increase in restricted assets	(6,872)	(1,108)
Issuance of notes receivable	(4,410)	(250)
Investments in subsidiaries	0	0
Proceeds from sale of fixed assets	3	4
Capital expenditures	(7,859)	(20,746)
Repayments of notes receivable	5,106	933
Pay downs of investment securities	5,743	690
Proceeds from sale of preferred securities	1,000	0
Investments in real estate held for sale	(12,512)	0
Net cash used in investing activities	(62,082)	(195,807)
Cash flows from financing activities:
Proceeds from issuance of debt	1,519	413,918
Deferred financing costs	(624)	(12,360)
Repayments of debt	(4,968)	(10,305)
Borrowings under revolver	130,691	645,894
Repayments on revolver	(146,655)	(673,866)
Capital contributions received	0	0
Intercompany dividends paid	0	0
Dividends and distributions on common stock	(139,430)	(122,051)
Distributions to non-controlling interest	(564)	(4,861)
Proceeds from exercise of Vector options	1,321	4,407
Tax benefit of options exercised	756	937
Net cash (used in) provided by financing activities	(157,954)	241,713
Net (decrease) increase in cash and cash equivalents	(80,018)	145,950
Cash and cash equivalents, beginning of period	326,365	234,466
Cash and cash equivalents, end of period	246,347	380,416
Parent/Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	84,832	23,189
Cash flows from investing activities:
Sale of investment securities	146,614	173,046
Maturities of investment securities	2,653	517
Purchase of investment securities	(156,521)	(310,934)
Proceeds from sale or liquidation of long-term investments	0	500
Purchase of long-term investments	(10,000)	(12,000)
Investments in real estate ventures	0	0
Purchase of subsidiaries		0
Distributions from investments in real estate ventures	0	0
Increase in cash surrender value of life insurance policies	(766)	0
Increase in restricted assets	(2)	188
Issuance of notes receivable	0	(35,000)
Investments in subsidiaries	(53,511)	(49,834)
Proceeds from sale of fixed assets	0	0
Capital expenditures	0	(11)
Repayments of notes receivable	1,106	35,933
Pay downs of investment securities	5,743	690
Proceeds from sale of preferred securities	0
Investments in real estate held for sale	0
Net cash used in investing activities	(64,684)	(196,905)
Cash flows from financing activities:
Proceeds from issuance of debt	0	408,750
Deferred financing costs	0	(12,360)
Repayments of debt	0	0
Borrowings under revolver	0	0
Repayments on revolver	0	0
Capital contributions received	0	0
Intercompany dividends paid	0	0
Dividends and distributions on common stock	(139,430)	(122,051)
Distributions to non-controlling interest	0	0
Proceeds from exercise of Vector options	1,321	4,407
Tax benefit of options exercised	756	937
Net cash (used in) provided by financing activities	(137,353)	279,683
Net (decrease) increase in cash and cash equivalents	(117,205)	105,967
Cash and cash equivalents, beginning of period	211,751	151,342
Cash and cash equivalents, end of period	94,546	257,309
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	168,095	98,319
Cash flows from investing activities:
Sale of investment securities	14,415	0
Maturities of investment securities	0	0
Purchase of investment securities	(6,324)	(1,985)
Proceeds from sale or liquidation of long-term investments	0	0
Purchase of long-term investments	0	0
Investments in real estate ventures	0	0
Purchase of subsidiaries		0
Distributions from investments in real estate ventures	0	0
Increase in cash surrender value of life insurance policies	(459)	(435)
Increase in restricted assets	(6,870)	(607)
Issuance of notes receivable	0	0
Investments in subsidiaries	0	0
Proceeds from sale of fixed assets	3	4
Capital expenditures	(3,305)	(15,121)
Repayments of notes receivable	0	0
Pay downs of investment securities	0	0
Proceeds from sale of preferred securities	0
Investments in real estate held for sale	0
Net cash used in investing activities	(2,540)	(18,144)
Cash flows from financing activities:
Proceeds from issuance of debt	1,519	40,168
Deferred financing costs	(624)	0
Repayments of debt	(4,786)	(41,485)
Borrowings under revolver	130,691	645,894
Repayments on revolver	(146,655)	(673,866)
Capital contributions received	5,633	10,800
Intercompany dividends paid	(134,215)	(54,000)
Dividends and distributions on common stock	0	0
Distributions to non-controlling interest	0	0
Proceeds from exercise of Vector options	0	0
Tax benefit of options exercised	0	0
Net cash (used in) provided by financing activities	(148,437)	(72,489)
Net (decrease) increase in cash and cash equivalents	17,118	7,686
Cash and cash equivalents, beginning of period	9,724	11,812
Cash and cash equivalents, end of period	26,842	19,498
Subsidiary Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	31,660	53,475
Cash flows from investing activities:
Sale of investment securities	0	0
Maturities of investment securities	0	0
Purchase of investment securities	0	0
Proceeds from sale or liquidation of long-term investments	182	49
Purchase of long-term investments	0	0
Investments in real estate ventures	(43,280)	(29,378)
Purchase of subsidiaries		(250)
Distributions from investments in real estate ventures	11,205	5,540
Increase in cash surrender value of life insurance policies	0	0
Increase in restricted assets	0	(689)
Issuance of notes receivable	(4,410)	(250)
Investments in subsidiaries	0	0
Proceeds from sale of fixed assets	0	0
Capital expenditures	(4,554)	(5,614)
Repayments of notes receivable	4,000	0
Pay downs of investment securities	0	0
Proceeds from sale of preferred securities	1,000
Investments in real estate held for sale	(12,512)
Net cash used in investing activities	(48,369)	(30,592)
Cash flows from financing activities:
Proceeds from issuance of debt	0	0
Deferred financing costs	0	0
Repayments of debt	(182)	(3,820)
Borrowings under revolver	0	0
Repayments on revolver	0	0
Capital contributions received	47,878	39,034
Intercompany dividends paid	(10,354)	(20,939)
Dividends and distributions on common stock	0	0
Distributions to non-controlling interest	(564)	(4,861)
Proceeds from exercise of Vector options	0	0
Tax benefit of options exercised	0	0
Net cash (used in) provided by financing activities	36,778	9,414
Net (decrease) increase in cash and cash equivalents	20,069	32,297
Cash and cash equivalents, beginning of period	104,890	71,312
Cash and cash equivalents, end of period	124,959	103,609
Consolidating Adjustments [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	(144,569)	(74,939)
Cash flows from investing activities:
Sale of investment securities	0	0
Maturities of investment securities	0	0
Purchase of investment securities	0	0
Proceeds from sale or liquidation of long-term investments	0	0
Purchase of long-term investments	0	0
Investments in real estate ventures	0	0
Purchase of subsidiaries		0
Distributions from investments in real estate ventures	0	0
Increase in cash surrender value of life insurance policies	0	0
Increase in restricted assets	0	0
Issuance of notes receivable	0	35,000
Investments in subsidiaries	53,511	49,834
Proceeds from sale of fixed assets	0	0
Capital expenditures	0	0
Repayments of notes receivable	0	(35,000)
Pay downs of investment securities	0	0
Proceeds from sale of preferred securities	0
Investments in real estate held for sale	0
Net cash used in investing activities	53,511	49,834
Cash flows from financing activities:
Proceeds from issuance of debt	0	(35,000)
Deferred financing costs	0	0
Repayments of debt	0	35,000
Borrowings under revolver	0	0
Repayments on revolver	0	0
Capital contributions received	(53,511)	(49,834)
Intercompany dividends paid	144,569	74,939
Dividends and distributions on common stock	0	0
Distributions to non-controlling interest	0	0
Proceeds from exercise of Vector options	0	0
Tax benefit of options exercised	0	0
Net cash (used in) provided by financing activities	91,058	25,105
Net (decrease) increase in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	$ 0	$ 0