Commitments and Contingencies Commitments and Contingencies - Guarantees (Details) - USD ($) $ in Thousands	Apr. 25, 2019	May 03, 2019	Mar. 31, 2019	Jan. 08, 2019
Financial Guarantee
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)			$ 51,080
Financial Guarantee | 1405 Point
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)			25,000
Financial Guarantee | The Residences at Annapolis Junction
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)			8,300
Financial Guarantee | Delray Plaza
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)			5,180	$ 5,200
Financial Guarantee | Nexton Square
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)			12,600
Financial Guarantee | Interlock Commercial
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)			$ 0
Forecast | Financial Guarantee | Interlock Commercial
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)		$ 30,700
Subsequent Event | First Purchase Option | 1405 Point
Commitments and Contingencies
Option to purchase additional voting rights	79.00%