2007
Schedule of Available-for-sale Securities [Line Items]Available-for-sale Securities, Debt Maturities [Abstract]Available-for-sale Securities, Debt Maturities, Amortized Cost [Abstract]Available-for-sale Securities, Debt Maturities, Amortized Cost, Excluding Securities without Single Maturity Dates [Abstract]Available-for-sale Securities, Debt Maturities, within One Year, Amortized CostMajor Types of Debt and Equity Securities [Domain]157,319,000
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Amortized CostMajor Types of Debt and Equity Securities [Domain]82,633,000
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Amortized CostMajor Types of Debt and Equity Securities [Domain]217,192,000
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized CostMajor Types of Debt and Equity Securities [Domain]116,415,000
Available-for-sale Securities, Debt Maturities, Amortized Cost, Excluding Securities without Single Maturity DatesMajor Types of Debt and Equity Securities [Domain]573,559,000
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized CostMortgage-backed Securities [Member]Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]1,678,828,000
Mortgage-backed Securities, Issued by Private Enterprises [Member]312,973,000
Major Types of Debt and Equity Securities [Domain]1,991,801,000
Available-for-sale Securities, Debt Maturities, Amortized CostMajor Types of Debt and Equity Securities [Domain]2,565,360,000
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]Available-for-sale Securities, Debt Maturities, Fair Value, Excluding Securities without Single Maturity Dates [Abstract]Available-for-sale Securities, Debt Maturities, within One Year, Fair ValueMajor Types of Debt and Equity Securities [Domain]156,912,000
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Fair ValueMajor Types of Debt and Equity Securities [Domain]82,341,000
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair ValueMajor Types of Debt and Equity Securities [Domain]218,091,000
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair ValueMajor Types of Debt and Equity Securities [Domain]116,935,000
Available-for-sale Securities, Debt Maturities, Fair Value, Excluding Securities without Single Maturity DatesMajor Types of Debt and Equity Securities [Domain]574,279,000
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair ValueMortgage-backed Securities [Member]Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]1,684,471,000
Mortgage-backed Securities, Issued by Private Enterprises [Member]304,440,000
Major Types of Debt and Equity Securities [Domain]1,988,911,000
Available-for-sale Securities, Debt Maturities, Fair ValueMajor Types of Debt and Equity Securities [Domain]2,563,190,000