Shareholder Report, Line Graph (Details) - USD ($)		12 Months Ended		24 Months Ended	36 Months Ended	48 Months Ended	60 Months Ended	72 Months Ended	84 Months Ended	96 Months Ended	108 Months Ended	120 Months Ended
	Apr. 30, 2015	Apr. 30, 2025	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2024	Apr. 30, 2025
C000005817 [Member]
Account Value [Line Items]
Line Graph and Table Measure Name		Institutional Shares
Accumulated Value	$ 10,000		$ 8,119	$ 9,863	$ 12,232	$ 12,209	$ 11,544	$ 18,136	$ 13,504	$ 13,065	$ 13,964	$ 13,839
C000005814 [Member]
Account Value [Line Items]
Line Graph and Table Measure Name		Investor A Shares (with sales charge)
C000005816 [Member]
Account Value [Line Items]
Line Graph and Table Measure Name		Investor C Shares (with sales charge)
C000198223 [Member]
Account Value [Line Items]
Line Graph and Table Measure Name		Class K Shares
Accumulated Value	10,000		8,119	9,863	12,237	12,219	11,563	18,168	13,536	13,097	14,011	13,893
MSCI Emerging Markets Index [Member]
Account Value [Line Items]
Line Graph and Table Measure Name		MSCI Emerging Markets Index
Accumulated Value	$ 10,000		$ 8,213	$ 9,785	$ 11,910	$ 11,309	$ 9,952	$ 14,800	$ 12,087	$ 11,300	$ 12,416	$ 13,537