Investments in Debt and Equity Securities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Amortized costs and fair values
Equity securities	$ 9,500	$ 5,005
Total, Amortized costs	445,690	449,552
Debt securities, Fair values	454,083
Equity securities, Fair values	10,268	5,443
Total, Fair values	464,351	460,985
Municipal [Member]
Amortized costs and fair values
Debt securities	20,313	26,721
Debt securities, Fair values	21,247	27,801
Corporate and utilities [Member]
Amortized costs and fair values
Debt securities	236,425	237,912
Debt securities, Fair values	250,026	244,123
Foreign [Member]
Amortized costs and fair values
Debt securities	161,871	162,384
Debt securities, Fair values	163,637	164,268
U.S. Government [Member]
Amortized costs and fair values
Debt securities	17,581	17,530
Debt securities, Fair values	$ 19,173	$ 19,350

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

Amount of debt securities categorized neither as held-to-maturity nor trading.

+ References

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+ Details

- Definition

Amount of equity securities categorized neither as held-to-maturity nor as trading.

+ References

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+ Details