Short- and Long-Term Investments and Investments on Deposit for Licensure (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012
Amortized cost and fair value of available-for-sale debt securities by contractual maturity
Maturing within one year, amortized cost	$ 505,042
Maturing within one year, fair value	506,170
Maturing between one year and five years, amortized cost	570,644
Maturing between one year and five years, fair value	578,694
Maturing between five years and ten years, amortized cost	238,334
Maturing between five years and ten years, fair value	252,493
Maturing in greater than ten years, amortized cost	81,742
Maturing in greater than ten years, fair value	84,047
Total, amortized cost	1,395,762
Total, fair value	$ 1,421,404

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Amount of available-for-sale debt securities at cost, net of adjustments, which include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the next rolling twelve months following the latest balance sheet presented. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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Amount of available-for-sale debt securities at fair value maturing in the next rolling twelve months following the latest balance sheet presented.

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Amount of available-for-sale debt securities at cost, net of adjustments, maturing after the tenth rolling twelve months following the latest balance sheet presented. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the sixth rolling twelve months through the tenth rolling twelve months following the latest balance sheet presented. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the second rolling twelve months through the fifth rolling twelve months following the latest balance sheet presented. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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

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