Long-term Debt Redemption Percentages for Future Periods (Details)	6 Months Ended
	Jun. 30, 2013
2015
Debt Instrument Redemption [Line Items]
Notes redemption percentages	104.062%
2016
Debt Instrument Redemption [Line Items]
Notes redemption percentages	102.031%
2017 and thereafter
Debt Instrument Redemption [Line Items]
Notes redemption percentages	100.00%