Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Compensation and management fee	$ 38,938	$ 36,048	$ 78,200	$ 73,045
Management Agreement
Basis for management fee			Amount equal to 1/12th of 1.05% of our stockholders' equity
Compensation and management fee	38,938	$ 36,048	$ 78,200	$ 73,045
Management fee payable	$ 11,800		$ 11,800		$ 11,200
Term of management agreement expiration date			Dec. 31, 2018
Renewal term			2 years
Management agreement, termination, description			At least two-thirds of the Company's independent directors or the holders of a majority of the Company's outstanding shares of common stock elect to terminate the agreement in their sole discretion for any or no reason.
Management Agreement | Minimum
Management agreement, required period to terminate from the date of the notice			1 year