Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Transfers between Level 1, 2 and 3 in fair value measurement hierarchy	$ 0	$ 0
Unfunded commitments	9,183,000		$ 10,242,000
EGCP III [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Unfunded commitments	$ 8,613,000
End of the investment period	Oct. 12, 2016
Remaining commitments date	Oct. 12, 2023