Subsequent Event (Details) (Subsequent Event [Member], Senior Notes [Member], USD $) In Millions, unless otherwise specified	Oct. 15, 2014
Three Point Nine Seven Percent Senior Notes [Member]
Subsequent Event [Line Items]
Principal amount of debt	$ 0
Stated interest rate	3.97%
Percent allowed to be prepaid	100.00%
Maximum [Member]
Subsequent Event [Line Items]
Debt covenant ratio of senior debt to EBITDA	3.25
Debt covenant ratio of total debt to EBITDA	4.00
Maximum [Member] | Adjusted for Certain Acquisitons [Member]
Subsequent Event [Line Items]
Debt covenant ratio of senior debt to EBITDA	3.50
Debt covenant ratio of total debt to EBITDA	4.25
Minimum [Member]
Subsequent Event [Line Items]
Debt covenant ratio of EBITDA to cash interest expense	4.25