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Fair Value Measurements (Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	$ 136,094	$ 209,544
Short-term debt	45,000	60,000
Long-term debt	378,551	328,192
Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	60,682	56,929
Six Point Seventy Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	118,192	110,363
Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	194,324	192,474
One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	25,048
One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	24,990
Long-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	423,236	359,766
Zero Point Sixty Three Percent Borrowing From Federal Home Loan Bank Due July 22, 2016 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt		14,977
One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt	45,072	45,083
Short-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt	45,072	60,060
Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	107,829	181,880
Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	25,851	22,015
Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	51	1,028
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	2,363	4,621
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Short-term debt	0	0
Long-term debt	194,324	192,474
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Six Point Seventy Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	194,324	192,474
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Zero Point Sixty Three Percent Borrowing From Federal Home Loan Bank Due July 22, 2016 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt		0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	128,403	206,208
Short-term debt	45,072	60,060
Long-term debt	228,912	167,292
Significant Other Observable Inputs (Level 2) [Member] | Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	60,682	56,929
Significant Other Observable Inputs (Level 2) [Member] | Six Point Seventy Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	118,192	110,363
Significant Other Observable Inputs (Level 2) [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Significant Other Observable Inputs (Level 2) [Member] | One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	25,048
Significant Other Observable Inputs (Level 2) [Member] | One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	24,990
Significant Other Observable Inputs (Level 2) [Member] | Zero Point Sixty Three Percent Borrowing From Federal Home Loan Bank Due July 22, 2016 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt		14,977
Significant Other Observable Inputs (Level 2) [Member] | One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt	45,072	45,083
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	107,829	181,880
Significant Other Observable Inputs (Level 2) [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	18,160	18,679
Significant Other Observable Inputs (Level 2) [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	51	1,028
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	2,363	4,621
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	7,691	3,336
Short-term debt	0	0
Long-term debt	0	0
Significant Unobservable Inputs (Level 3) [Member] | Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Significant Unobservable Inputs (Level 3) [Member] | Six Point Seventy Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Significant Unobservable Inputs (Level 3) [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Significant Unobservable Inputs (Level 3) [Member] | One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0
Significant Unobservable Inputs (Level 3) [Member] | Zero Point Sixty Three Percent Borrowing From Federal Home Loan Bank Due July 22, 2016 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt		0
Significant Unobservable Inputs (Level 3) [Member] | One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt	0	0
Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	7,691	3,336
Significant Unobservable Inputs (Level 3) [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	$ 0	$ 0

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Fair value of investments in debt securities classified as held-to-maturity.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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