Fair Value Measurements - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Fair Value, Option, Quantitative Disclosures [Line Items]
Transfers between Level 1 , 2 and 3 in fair value measurement hierarchy	$ 0	$ 0
Unfunded Commitments	27,156		27,135
CP II [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Unfunded Commitments	1,940
End of the investment period	Feb. 25, 2017
EGCP III [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Unfunded Commitments	18,337
End of the investment period	Oct. 12, 2016
Remaining commitments date	Oct. 12, 2023
COF2 [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Unfunded Commitments	$ 6,879
End of the investment period	Nov. 11, 2016
Remaining commitments date	Nov. 11, 2019