Condensed Consolidating Financial Information Statements of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	$ 83,885	$ 53,995
Cash flows from investing activities:
Sale of investment securities	118,261	49,296
Maturities of investment securities	1,737	0
Purchase of investment securities	(113,595)	(110,419)
Proceeds from sale or liquidation of long-term investments	148	549
Purchase of long-term investments	(5,000)	(7,000)
Investments in real estate ventures	(34,857)	(12,534)
Purchase of subsidiaries	0	(250)
Distributions from investments in real estate ventures	0	3,539
Increase in cash surrender value of life insurance policies	(1,118)	(395)
Increase in restricted assets	(7,934)	(371)
Issuance of notes receivable	(4,410)	(250)
Investments in subsidiaries	0	0
Proceeds from sale of fixed assets	3	4
Capital expenditures	(5,379)	(10,144)
Repayments of notes receivable	1,106	933
Pay downs of investment securities	3,530	0
Proceeds from sale of preferred securities	1,000	0
Investments in real estate held for sale	(12,502)	0
Net cash used in investing activities	(59,010)	(87,042)
Cash flows from financing activities:
Proceeds from issuance of debt	22	413,916
Deferred financing costs	(625)	(12,360)
Repayments of debt	(3,374)	(8,051)
Borrowings under revolver	126,727	429,188
Repayments on revolver	(144,492)	(437,736)
Capital contributions received	0	0
Intercompany dividends paid	0	0
Dividends and distributions on common stock	(92,778)	(80,963)
Distributions to non-controlling interest	0	(3,075)
Proceeds from exercise of Vector options	1,219	3,405
Tax benefit of options exercised	384	680
Net cash (used in) provided by financing activities	(112,917)	305,004
Net (decrease) increase in cash and cash equivalents	(88,042)	271,957
Cash and cash equivalents, beginning of period	326,365	234,466
Cash and cash equivalents, end of period	238,323	506,423
Parent/Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	42,679	17,374
Cash flows from investing activities:
Sale of investment securities	103,846	49,296
Maturities of investment securities	1,737
Purchase of investment securities	(112,119)	(108,859)
Proceeds from sale or liquidation of long-term investments	0	500
Purchase of long-term investments	(5,000)	(7,000)
Investments in real estate ventures	0	0
Purchase of subsidiaries		0
Distributions from investments in real estate ventures		0
Increase in cash surrender value of life insurance policies	(717)	0
Increase in restricted assets	(1,327)	299
Issuance of notes receivable	0	(35,000)
Investments in subsidiaries	(42,808)	(25,267)
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	3,530
Proceeds from sale of preferred securities	0
Investments in real estate held for sale	0
Net cash used in investing activities	(51,752)	(90,109)
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	(92,778)	(80,963)
Distributions to non-controlling interest	0	0
Proceeds from exercise of Vector options	1,219	3,405
Tax benefit of options exercised	384	680
Net cash (used in) provided by financing activities	(91,175)	319,512
Net (decrease) increase in cash and cash equivalents	(100,248)	246,777
Cash and cash equivalents, beginning of period	211,751	151,342
Cash and cash equivalents, end of period	111,503	398,119
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	99,159	46,294
Cash flows from investing activities:
Sale of investment securities	14,415	0
Maturities of investment securities	0
Purchase of investment securities	(1,476)	(1,560)
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
Increase in cash surrender value of life insurance policies	(401)	(395)
Increase in restricted assets	(6,607)	19
Issuance of notes receivable	0	0
Investments in subsidiaries	0	0
Proceeds from sale of fixed assets	3	4
Capital expenditures	(2,350)	(6,563)
Repayments of notes receivable	0	0
Pay downs of investment securities	0
Proceeds from sale of preferred securities	0
Investments in real estate held for sale	0
Net cash used in investing activities	3,584	(8,495)
Cash flows from financing activities:
Proceeds from issuance of debt	22	40,166
Deferred financing costs	(625)	0
Repayments of debt	(3,254)	(39,293)
Borrowings under revolver	126,727	429,188
Repayments on revolver	(144,492)	(437,736)
Capital contributions received	2,250	3,150
Intercompany dividends paid	(69,075)	(30,000)
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	(88,447)	(34,525)
Net (decrease) increase in cash and cash equivalents	14,296	3,274
Cash and cash equivalents, beginning of period	9,724	11,812
Cash and cash equivalents, end of period	24,020	15,086
Subsidiary Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	13,057	32,279
Cash flows from investing activities:
Sale of investment securities	0	0
Maturities of investment securities	0
Purchase of investment securities	0	0
Proceeds from sale or liquidation of long-term investments	148	49
Purchase of long-term investments	0	0
Investments in real estate ventures	(34,857)	(12,534)
Purchase of subsidiaries		(250)
Distributions from investments in real estate ventures		3,539
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	(3,029)	(3,570)
Repayments of notes receivable	0	0
Pay downs of investment securities	0
Proceeds from sale of preferred securities	1,000
Investments in real estate held for sale	(12,502)
Net cash used in investing activities	(53,650)	(13,705)
Cash flows from financing activities:
Proceeds from issuance of debt	0	0
Deferred financing costs	0	0
Repayments of debt	(120)	(3,758)
Borrowings under revolver	0	0
Repayments on revolver	0	0
Capital contributions received	40,558	22,117
Intercompany dividends paid	(1,935)	(11,952)
Dividends and distributions on common stock	0	0
Distributions to non-controlling interest	0	(3,075)
Proceeds from exercise of Vector options	0	0
Tax benefit of options exercised	0	0
Net cash (used in) provided by financing activities	38,503	3,332
Net (decrease) increase in cash and cash equivalents	(2,090)	21,906
Cash and cash equivalents, beginning of period	104,890	71,312
Cash and cash equivalents, end of period	102,800	93,218
Consolidating Adjustments [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	(71,010)	(41,952)
Cash flows from investing activities:
Sale of investment securities	0	0
Maturities of investment securities	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
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	42,808	25,267
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
Proceeds from sale of preferred securities	0
Investments in real estate held for sale	0
Net cash used in investing activities	42,808	25,267
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	(42,808)	(25,267)
Intercompany dividends paid	71,010	41,952
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	28,202	16,685
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