Subsequent Event (Details) (USD $) In Millions	0 Months Ended
	Jul. 07, 2011	Jun. 30, 2011
Maturity date of new credit facility	July 6, 2015
Line of credit facility, interest rate	LIBOR plus 115 basis points
Line of Credit Facility, Maximum Borrowing Capacity		$ 300.0
Existing Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	300.0
New Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	400.0