Investments (Realized Gains (Losses)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Held to maturity debt securities:
Equity securities realized gains	$ 2,700
Real estate		2,485	(70)	(178)
Mortgage loans		(638)	(609)	(387)
Other		0	233	235
Gain (Loss) on Investments, Excluding Other than Temporary Impairments		14,541	6,202	6,204
Realized gains (losses) on investments		13,200	6,063	5,475
Debt Securities [Member]
Available for sale debt securities:
Realized gains on disposal		7,115	6,448	4,174
Realized losses on disposal		0	(1)	(153)
Held to maturity debt securities:
Realized gains on redemption		6,065	763	2,407
Realized losses on redemption		(679)	(853)	0
Realized gains (losses) on investments		14,500	6,200	6,200
Equity Securities [Member]
Held to maturity debt securities:
Equity securities realized gains		$ 193	$ 291	$ 106

Held to Maturity, Realized Gain on Redemption

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Held to Maturity, Realized Losses on Redemption

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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The gains (losses) included in earnings resulting from the sale or disposal of tangible assets. This item does not include any gain (loss) recognized on the sale of oil and gas property or timber property.

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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

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The gains (losses) included in earnings that represent the difference between the sale price and the carrying value of loans made to finance real estate acquisitions. This element refers to the gain (loss) and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

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The net gain (loss) realized from the sale, exchange, redemption, or retirement of securities, not separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

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The net gain (loss) resulting from sales and other disposals of real estate owned for investment purposes.

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The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

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