Significant Accounting Policies Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Estimate of Fair Value, Fair Value Disclosure [Member]
Bond Portfolio at fair market value	$ 25,050	$ 24,887
Interest Rate Swap Agreement Fair Value Liability Disclosure	20,992	46,090
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	46,042	70,977
Fair Value, Inputs, Level 1 [Member]
Bond Portfolio at fair market value	0	0
Interest Rate Swap Agreement Fair Value Liability Disclosure	0	0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member]
Bond Portfolio at fair market value	25,050	24,887
Interest Rate Swap Agreement Fair Value Liability Disclosure	20,992	46,090
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	46,042	70,977
Fair Value, Inputs, Level 3 [Member]
Bond Portfolio at fair market value	0	0
Interest Rate Swap Agreement Fair Value Liability Disclosure	0	0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	$ 0	$ 0