Redeemable Preferred Shares - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Jan. 23, 2018	Dec. 15, 2010	Jan. 31, 2009	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2010
Class of Stock [Line Items]
Preferred shares authorized converted (in shares)							375,000
Goldman | Common Stock
Class of Stock [Line Items]
Shares converted (in shares)	28,808,224
CMHI | Common Stock
Class of Stock [Line Items]
Shares converted (in shares)	4,432,034
Series A Preferred Shares
Class of Stock [Line Items]
Number of shares issued (in shares)			125
Series A par value (in USD per share)			$ 0.01
Proceeds from issuance of shares			$ 100
Redemption price as a percentage of liquidation value			100.00%
Liquidation value (in USD per share)			$ 1,000
Dividend rate			12.50%
Redemption and distributions paid on preferred shares of beneficial interest – Series A	$ 100
Series B Preferred Shares
Class of Stock [Line Items]
Number of shares issued (in shares)		375,000
Proceeds from issuance of shares		$ 368,500
Shares authorized (in shares)							375,000
Series B par value (in USD per share)		$ 0.01					$ 0.01
Payment of accrued and unpaid dividends	$ 1,800				$ 0	$ 1,817
Series B Preferred Shares | Common Stock
Class of Stock [Line Items]
Shares converted (in shares)				33,240,258
Series B Preferred Shares | Goldman
Class of Stock [Line Items]
Number of shares issued (in shares)		325,000
Series B Preferred Shares | CMHI
Class of Stock [Line Items]
Number of shares issued (in shares)		50,000