Fair Value of Assets and Liabilities (Details Textual)	Jun. 30, 2013	Mar. 19, 2013
Fair Value of Assets and Liabilities (Textual) [Abstract]
Interest rate	7.75%
Senior Note Due 2017
Fair Value of Assets and Liabilities (Textual) [Abstract]
Interest rate	7.75%
Senior Notes Due 2021
Fair Value of Assets and Liabilities (Textual) [Abstract]
Interest rate	6.625%
Senior Notes Due 2023
Fair Value of Assets and Liabilities (Textual) [Abstract]
Interest rate		5.125%
Senior Unsecured Notes Due April 2023 | Senior Notes
Fair Value of Assets and Liabilities (Textual) [Abstract]
Interest rate	5.125%	5.125%