DERIVATIVES AND HEDGING - Summary of Net Forward Currency Sell Contracts Under Freestanding Derivatives (Detail) - Not Designated as Hedging Instrument - Foreign Currency Forward Sell Contracts € in Thousands, ¥ in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2016 JPY (¥)	Jun. 30, 2016 EUR (€)	Dec. 31, 2015 JPY (¥)	Dec. 31, 2015 EUR (€)
Derivative [Line Items]
Contract amount	$ 456,113	$ 393,360
Market Value in U.S. Dollars	466,380	390,771
Net Unrealized Appreciation (Depreciation)	(10,267)	2,589
Euro
Derivative [Line Items]
Contract amount	307,020	274,135		€ 273,050		€ 246,850
Market Value in U.S. Dollars	304,905	269,603
Net Unrealized Appreciation (Depreciation)	$ 2,115	$ 4,532
Euro | Minimum
Derivative [Line Items]
Expiration date	Jul. 08, 2016	Jan. 08, 2016
Euro | Maximum
Derivative [Line Items]
Expiration date	Sep. 29, 2017	Dec. 30, 2016
USD
Derivative [Line Items]
Contract amount	$ 92,963	$ 70,594
Market Value in U.S. Dollars	102,697	72,476
Net Unrealized Appreciation (Depreciation)	$ (9,734)	$ (1,882)
USD | Minimum
Derivative [Line Items]
Expiration date	Jul. 29, 2016	Jan. 08, 2016
USD | Maximum
Derivative [Line Items]
Expiration date	Jul. 31, 2017	Oct. 31, 2016
Japanese Yen
Derivative [Line Items]
Contract amount	$ 56,130	$ 48,631	¥ 6,051,400		¥ 5,840,300
Market Value in U.S. Dollars	58,778	48,692
Net Unrealized Appreciation (Depreciation)	$ (2,648)	$ (61)
Expiration date	Sep. 30, 2016
Japanese Yen | Minimum
Derivative [Line Items]
Expiration date		Jan. 29, 2016
Japanese Yen | Maximum
Derivative [Line Items]
Expiration date		Sep. 30, 2016