Derivative Instruments and Hedging Activity (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2009 Interest Rate Swap Agreement One [Member]	Dec. 31, 2012 Interest Rate Swap Agreement Two [Member]	Dec. 31, 2012 Interest Rate Swap Agreement Three [Member]
Derivative, Notional Amount	$ 24,501,280	$ 22,268,358	$ 25,000,000
Derivative, Inception Date	Jan. 02, 2009	Jul. 01, 2013	Dec. 06, 2012
Derivative, Maturity Date	Jul. 01, 2013	May 01, 2019	Apr. 04, 2018
Description Of Interest Rate Cash Flow Hedge Activities	1.5% plus one-month LIBOR and will pay to the counterparty a fixed rate of 3.744%.	one-month LIBOR and will pay to the counterparty a fixed rate of 1.92%.	one month LIBOR and will pay to the counterparty a fixed rate of .885%.
Short-Term Debt, Percentage Bearing Fixed Interest Rate	3.744%	1.92%	0.885%
Conversion Of Variable Rate Borrowing Amount To Fixed Rate Bearing Amount	$ 24,501,280	$ 22,268,358	$ 25,000,000