Condensed Consolidating Financial Information Statements of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 7,828	$ (39,084)
Cash flows from investing activities:
Sale of investment securities	75,538	35,009
Purchase of investment securities	(67,628)	(36,763)
Proceeds from sale or liquidation of long-term investments	110	0
Purchase of long-term investments	(5,000)	(1,000)
Investments in real estate ventures	(7,816)	(4,068)
Distributions from investments in real estate ventures	0	2,575
Increase in cash surrender value of life insurance policies	(606)	(47)
Increase in restricted assets	(6,933)	(390)
Issuance of notes receivable		0
Investments in subsidiaries	0	0
Proceeds from sale of fixed assets	3	0
Capital expenditures	(3,156)	(6,424)
Repayments of notes receivable	1,106	933
Pay downs of investment securities	1,594	0
Net cash used in investing activities	(12,788)	(10,175)
Cash flows from financing activities:
Proceeds from issuance of debt	0	260,508
Deferred financing costs	(585)	(8,210)
Repayments of debt	(1,857)	(2,215)
Borrowings under revolver	107,668	196,842
Repayments on revolver	(110,792)	(211,520)
Capital contributions received	0	0
Intercompany dividends paid	0	0
Dividends and distributions on common stock	(46,350)	(40,865)
Proceeds from exercise of Vector options	809	1,385
Tax benefit of options exercised	274	344
Net cash (used in) provided by financing activities	(50,833)	196,269
Net (decrease) increase in cash and cash equivalents	(55,793)	147,010
Cash and cash equivalents, beginning of period	326,365	234,466
Cash and cash equivalents, end of period	270,572	381,476
Parent/Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(1,451)	(36,859)
Cash flows from investing activities:
Sale of investment securities	61,123	35,009
Purchase of investment securities	(66,152)	(36,763)
Proceeds from sale or liquidation of long-term investments	0
Purchase of long-term investments	(5,000)	(1,000)
Investments in real estate ventures	0	0
Distributions from investments in real estate ventures		0
Increase in cash surrender value of life insurance policies	(558)	0
Increase in restricted assets	(1)	300
Issuance of notes receivable		(35,000)
Investments in subsidiaries	(1,969)	(7,081)
Proceeds from sale of fixed assets	0
Capital expenditures	0	0
Repayments of notes receivable	1,106	10,933
Pay downs of investment securities	1,594
Net cash used in investing activities	(9,857)	(33,602)
Cash flows from financing activities:
Proceeds from issuance of debt		258,750
Deferred financing costs	0	(8,210)
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	(46,350)	(40,865)
Proceeds from exercise of Vector options	809	1,385
Tax benefit of options exercised	274	344
Net cash (used in) provided by financing activities	(45,267)	211,404
Net (decrease) increase in cash and cash equivalents	(56,575)	140,943
Cash and cash equivalents, beginning of period	211,751	151,342
Cash and cash equivalents, end of period	155,176	292,285
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	58,885	1,776
Cash flows from investing activities:
Sale of investment securities	14,415	0
Purchase of investment securities	(1,476)	0
Proceeds from sale or liquidation of long-term investments	0
Purchase of long-term investments	0	0
Investments in real estate ventures	0	0
Distributions from investments in real estate ventures		0
Increase in cash surrender value of life insurance policies	(48)	(47)
Increase in restricted assets	(6,932)	(1)
Issuance of notes receivable		0
Investments in subsidiaries	0	0
Proceeds from sale of fixed assets	3
Capital expenditures	(956)	(4,551)
Repayments of notes receivable	0	0
Pay downs of investment securities	0
Net cash used in investing activities	5,006	(4,599)
Cash flows from financing activities:
Proceeds from issuance of debt		36,758
Deferred financing costs	(585)	0
Repayments of debt	(1,797)	(12,120)
Borrowings under revolver	107,668	196,842
Repayments on revolver	(110,792)	(211,520)
Capital contributions received	1,950	350
Intercompany dividends paid	(43,955)	0
Dividends and distributions on common stock	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	(47,511)	10,310
Net (decrease) increase in cash and cash equivalents	16,380	7,487
Cash and cash equivalents, beginning of period	9,724	11,812
Cash and cash equivalents, end of period	26,104	19,299
Subsidiary Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(4,122)	1,880
Cash flows from investing activities:
Sale of investment securities	0	0
Purchase of investment securities	0	0
Proceeds from sale or liquidation of long-term investments	110
Purchase of long-term investments	0	0
Investments in real estate ventures	(7,816)	(4,068)
Distributions from investments in real estate ventures		2,575
Increase in cash surrender value of life insurance policies	0	0
Increase in restricted assets	0	(689)
Issuance of notes receivable		0
Investments in subsidiaries	0	0
Proceeds from sale of fixed assets	0
Capital expenditures	(2,200)	(1,873)
Repayments of notes receivable	0	0
Pay downs of investment securities	0
Net cash used in investing activities	(9,906)	(4,055)
Cash flows from financing activities:
Proceeds from issuance of debt		0
Deferred financing costs	0	0
Repayments of debt	(60)	(95)
Borrowings under revolver	0	0
Repayments on revolver	0	0
Capital contributions received	19	6,731
Intercompany dividends paid	(1,529)	(5,881)
Dividends and distributions on common stock	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	(1,570)	755
Net (decrease) increase in cash and cash equivalents	(15,598)	(1,420)
Cash and cash equivalents, beginning of period	104,890	71,312
Cash and cash equivalents, end of period	89,292	69,892
Consolidating Adjustments [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(45,484)	(5,881)
Cash flows from investing activities:
Sale of investment securities	0	0
Purchase of investment securities	0	0
Proceeds from sale or liquidation of long-term investments	0
Purchase of long-term investments	0	0
Investments in real estate ventures	0	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		35,000
Investments in subsidiaries	1,969	7,081
Proceeds from sale of fixed assets	0
Capital expenditures	0	0
Repayments of notes receivable	0	(10,000)
Pay downs of investment securities	0
Net cash used in investing activities	1,969	32,081
Cash flows from financing activities:
Proceeds from issuance of debt		(35,000)
Deferred financing costs	0	0
Repayments of debt	0	10,000
Borrowings under revolver	0	0
Repayments on revolver	0	0
Capital contributions received	(1,969)	(7,081)
Intercompany dividends paid	45,484	5,881
Dividends and distributions on common stock	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	43,515	(26,200)
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