Related Party Transactions (Summary of Revenue Recognized/Amounts Paid Related to Service Provided to/from Portfolio Companies) (Details) - Blackstone Portfolio Companies [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Related Party Transaction [Line Items]
Revenue recognized related to services provided	$ 838		$ 1,881
Amount paid related to services received	$ 4,166		$ 9,458