XML 42 R26.htm IDEA: XBRL DOCUMENT v3.5.0.2
Significant Accounting Policies - Creations and Redemptions of Shares (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2014
Activity in Number of Shares Issued and Outstanding:      
Creations 174,700,000 55,100,000 47,200,000
Redemptions (86,000,000) (81,700,000) (91,500,000)
Net increase/(decrease) Shares Issued and Outstanding 88,700,000 (26,600,000) (44,300,000)
Activity in Value of Shares Issued and Outstanding:      
Creations $ 20,832,493 $ 6,447,849 [1] $ 5,893,107
Redemptions (10,102,639) (9,247,346) [1] (11,209,535)
Net increase/(decrease) Shares Issued and Outstanding $ 10,729,854 $ (2,799,497) $ (5,316,428)
[1] Effective October 1, 2014, the Trust adopted the financial presentation provisions for an investment company. See note 2.2 to our audited financial statements.