Credit Facility	3 Months Ended
Mar. 31, 2012
Credit Facility [Abstract]
Credit Facility	5. Credit Facility We have a $425 million revolving, unsecured credit facility, with an initial term that expires in March 2014, and includes two, one-year extension options. Under this credit facility, the current investment grade credit ratings on our debt securities 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 under this credit facility. 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 March 31, 2012, the balance of these credit facility origination costs was $2.8 million and at December 31, 2011 was $3.1 million, which is being amortized over the remaining term of the credit facility. At March 31, 2012, we had a borrowing capacity of $382.0 million available on our credit facility (subject to customary conditions to borrowing) and an outstanding balance of $43.0 million, as compared to an outstanding balance of $237.4 million at December 31, 2011. The average interest rate on outstanding borrowings under our credit facility was 2.1% during the first three months of 2012 and 2011. Our credit facility is subject to various leverage and interest coverage ratio limitations. At March 31, 2012, we remain in compliance with these covenants. We regularly review our credit facility and may seek to extend, renew or replace our credit facility, to the extent we deem appropriate.

5. Credit Facility

We have a $425 million revolving, unsecured credit facility, with an initial term that expires in March 2014, and includes two, one-year extension options. Under this credit facility, the current investment grade credit ratings on our debt securities 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 under this credit facility. 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 March 31, 2012, the balance of these credit facility origination costs was $2.8 million and at December 31, 2011 was $3.1 million, which is being amortized over the remaining term of the credit facility.

At March 31, 2012, we had a borrowing capacity of $382.0 million available on our credit facility (subject to customary conditions to borrowing) and an outstanding balance of $43.0 million, as compared to an outstanding balance of $237.4 million at December 31, 2011.

The average interest rate on outstanding borrowings under our credit facility was 2.1% during the first three months of 2012 and 2011. Our credit facility is subject to various leverage and interest coverage ratio limitations. At March 31, 2012, we remain in compliance with these covenants.

We regularly review our credit facility and may seek to extend, renew or replace our credit facility, to the extent we deem appropriate.