Credit Facility	6 Months Ended
Jun. 30, 2011
Credit Facility [Abstract]
Credit Facility	4. Credit Facility In December 2010, we entered into a $425 million revolving, unsecured credit facility that replaced our previous $355 million acquisition credit facility that was scheduled to expire in May 2011. The initial term of the credit facility expires in March 2014 and includes two, one-year extension options. Under this credit facility, our investment grade credit ratings provide for financing at the London Interbank Offered Rate, commonly referred to as LIBOR, plus 185 basis points with a facility commitment fee of 35 basis points, for all-in drawn pricing of 220 basis points over LIBOR. The borrowing rate is not subject to an interest rate floor or ceiling. We also have other interest rate options available to us. Our credit facility is unsecured and, accordingly, we have not pledged any assets as collateral for this obligation. As a result of entering into our current credit facility, we incurred credit facility origination costs of $4.2 million that were classified as part of "other assets" on our consolidated balance sheet at December 31, 2010. At June 30, 2011, the balance of these credit facility origination costs was $3.5 million, which is being amortized over the remaining term of the credit facility. The average borrowing rate on our credit facility during the first six months of 2011 was 2.1% and, during the first six months of 2010, was 1.3%. Our borrowing rate at June 30, 2011 was 2.0%, and at June 30, 2010 was 1.3%. Our current and prior credit facilities are subject to various leverage and interest coverage ratio limitations. We are and have been in compliance with these covenants.

Credit Facility

6 Months Ended

Jun. 30, 2011

4. Credit Facility

In December 2010, we entered into a $425 million revolving, unsecured credit facility that replaced our previous $355 million acquisition credit facility that was scheduled to expire in May 2011. The initial term of the credit facility expires in March 2014 and includes two, one-year extension options. Under this credit facility, our investment grade credit ratings provide for financing at the London Interbank Offered Rate, commonly referred to as LIBOR, plus 185 basis points with a facility commitment fee of 35 basis points, for all-in drawn pricing of 220 basis points over LIBOR. The borrowing rate is not subject to an interest rate floor or ceiling. We also have other interest rate options available to us. Our credit facility is unsecured and, accordingly, we have not pledged any assets as collateral for this obligation.

As a result of entering into our current credit facility, we incurred credit facility origination costs of $4.2 million that were classified as part of "other assets" on our consolidated balance sheet at December 31, 2010. At June 30, 2011, the balance of these credit facility origination costs was $3.5 million, which is being amortized over the remaining term of the credit facility.

The average borrowing rate on our credit facility during the first six months of 2011 was 2.1% and, during the first six months of 2010, was 1.3%. Our borrowing rate at June 30, 2011 was 2.0%, and at June 30, 2010 was 1.3%. Our current and prior credit facilities are subject to various leverage and interest coverage ratio limitations. We are and have been in compliance with these covenants.