Condensed Consolidating Financial Information (Details Textual) (USD $)	Dec. 31, 2012	Jan. 01, 2012	Aug. 31, 2010	Dec. 31, 2012 Senior Notes Due 2012 [Member]	Aug. 12, 2010 Senior Notes Due 2012 [Member]	Dec. 31, 2012 Senior Note Due 2017 [Member]	Aug. 22, 2011 Senior Note Due 2017 [Member]	Feb. 10, 2011 Senior Note Due 2017 [Member]	Oct. 20, 2009 Senior Note Due 2017 [Member]	Dec. 31, 2012 Senior Notes Due 2021 [Member]	Feb. 10, 2011 Senior Notes Due 2021 [Member]	Oct. 20, 2009 Senior Note Issued October 20, 2009 [Member]
Debt Instrument [Line Items]
Notes bear interest at a rate			8.47%	6.625%	10.75%	7.75%		6.625%	7.75%	6.625%	6.625%	7.75%
Condensed Consolidating Financial Information (Textual) [Abstract]
Aggregate principal amount of taxable revenue bonds	$ 49,500,000	$ 250,000,000					$ 300,000,000				$ 300,000,000
Percentage of subsidiary owned	100.00%