Schedule of VIEs (Details) - Variable Interest Entity, Primary Beneficiary, Aggregated Disclosure - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
NHP/PMB L.P.
Variable Interest Entity [Line Items]
Total assets	$ 673,467	$ 605,150
Total liabilities	238,147	199,958
Other Identified VIEs
Variable Interest Entity [Line Items]
Total assets	2,075,499	1,983,183
Total liabilities	402,478	348,124
Tax Credit VIEs
Variable Interest Entity [Line Items]
Total assets	797,077	988,598
Total liabilities	$ 298,154	$ 221,908