Commitments and Contingencies - Construction Activity (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) ft² property
Other Commitments [Line Items]
Number of Properties | property	198
Approximate Square Feet | ft²	14,300,000
Medical Office Buildings and Retail Sites [Member]
Other Commitments [Line Items]
Construction in Progress Fundings During the Twelve Months Ended	$ 19,024
Total Funded During the Twelve Months Ended	27,859
Total Amount Funded	32,243
Estimated Remaining Fundings (unaudited)	67,032
Estimated Total Investment (unaudited)	$ 99,275
Approximate Square Feet | ft²	542,900
Alabama [Member]
Other Commitments [Line Items]
Total Amount Funded	$ 6,900
Estimated Remaining Fundings (unaudited)	8,500
Estimated Total Investment (unaudited)	$ 15,400
Alabama [Member] | Medical Office Building [Member]
Other Commitments [Line Items]
Number of Properties | property	1
Construction in Progress Fundings During the Twelve Months Ended	$ 0
Total Funded During the Twelve Months Ended	6,880
Total Amount Funded	6,880
Estimated Remaining Fundings (unaudited)	8,520
Estimated Total Investment (unaudited)	$ 15,400
Approximate Square Feet | ft²	138,000
Texas [Member] | Retail Site [Member]
Other Commitments [Line Items]
Number of Properties | property	1
Construction in Progress Fundings During the Twelve Months Ended	$ 3,316
Total Funded During the Twelve Months Ended	3,316
Total Amount Funded	3,316
Estimated Remaining Fundings (unaudited)	2,259
Estimated Total Investment (unaudited)	$ 5,575
Approximate Square Feet | ft²	12,900
Tennessee [Member]
Other Commitments [Line Items]
Number of Properties | property	2
Total Amount Funded	$ 21,800
Estimated Total Investment (unaudited)	$ 51,800
Tennessee [Member] | Medical Office Building [Member]
Other Commitments [Line Items]
Number of Properties | property	2,000
Construction in Progress Fundings During the Twelve Months Ended	$ 15,479
Total Funded During the Twelve Months Ended	17,434
Total Amount Funded	21,818
Estimated Remaining Fundings (unaudited)	29,982
Estimated Total Investment (unaudited)	$ 51,800
Approximate Square Feet | ft²	294,000
Colorado [Member] | Retail Site [Member]
Other Commitments [Line Items]
Construction in Progress Fundings During the Twelve Months Ended	$ 229
Estimated Total Investment (unaudited)	$ 26,500
Approximate Square Feet | ft²	98,000
Colorado [Member] | Medical Office Building [Member]
Other Commitments [Line Items]
Number of Properties | property	1
Construction in Progress Fundings During the Twelve Months Ended	$ 229
Total Funded During the Twelve Months Ended	229
Total Amount Funded	229
Estimated Remaining Fundings (unaudited)	26,271
Estimated Total Investment (unaudited)	$ 26,500
Approximate Square Feet | ft²	98,000
Parking Garage [Member] | Alabama [Member] | Medical Office Building [Member]
Other Commitments [Line Items]
Estimated Total Investment (unaudited)	$ 5,900
Tenant Improvement Allowances and Commissions [Member] | Alabama [Member] | Medical Office Building [Member]
Other Commitments [Line Items]
Estimated Total Investment (unaudited)	$ 9,500