Debt Preceding Credit Facility and 8 7/8 Senior Notes (Details) (USD $)	1 Months Ended		9 Months Ended
	Aug. 31, 2011	Jul. 31, 2011	Sep. 30, 2012	Sep. 30, 2011
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			4.25%	4.25%
Repayments of Senior Debt	$ 44,000,000	$ 133,000,000
8 7/8 Senior Notes tender offer amounts (as a percent of par value)		103.333%
8 7/8 Senior Notes redemption amount	102.958%
Expenses related to refinancing activity			$ 0	$ (10,835,000)
8.875% Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			8.875%