Combined Schedules of Investments (Parenthetical) - USD ($)		3 Months Ended	6 Months Ended
		Jun. 30, 2019	Dec. 31, 2019
SIT RISING RATE ETF
Investment owned, Percent of net assets		100.00%	100.00%
BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Percent of net assets		100.00%	100.00%
Purchased Options | SIT RISING RATE ETF
Investment owned, Percent of net assets			(0.40%)
Purchased Options | U.S. Treasury 10 Year Note | SIT RISING RATE ETF
Investment owned, Subject to option, Price		$ 123.50	$ 129.50
Investment owned, Subject to option, Exercise dates		08/23/2019	02/21/2020
Investment owned, at cost		$ 58,883	$ 17,862
Investment owned, Percent of net assets		0.30%	0.30%
Purchased Options | U.S. Treasury 10 Year Note | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, at cost			$ 0
Investment owned, Percent of net assets		2.082%	0.00%
Written Options Contracts | SIT RISING RATE ETF
Investment owned, Percent of net assets			0.00%
Written Options Contracts | U.S. Treasury 5 Year Note | SIT RISING RATE ETF
Investment owned, Subject to option, Price		$ 117.75	$ 118.50
Investment owned, Subject to option, Exercise dates		08/23/2019	02/21/2020
Investment owned premiums received		$ 16,128	$ 7,366
Short Futures Contracts | U.S. Treasury 10 Year Note | SIT RISING RATE ETF
Investment owned, at cost		11,586,722	5,343,883
Investment owned, Principal amount		11,700,000	5,350,000	[1]
Short Futures Contracts | U.S. Treasury 5 Year Note | SIT RISING RATE ETF
Investment owned, Principal amount		12,051,938	11,852,500
Short Futures Contracts | U.S. Treasury 2 Year Note | SIT RISING RATE ETF
Investment owned, Principal amount		22,809,047	5,456,031
Money Market Funds | SIT RISING RATE ETF
Investment owned, at cost		$ 282,538	$ 166,948
Investment owned, Percent of net assets		1.40%	2.90%
Money Market Funds | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, at cost		$ 1,095,625	$ 551,232
Investment owned, Percent of net assets		25.40%	23.90%
Money Market Funds | First American US Treasury Money Market Fund Class Z | SIT RISING RATE ETF
Investment owned, at cost		$ 282,538	$ 166,948	[2]
Investment owned, Percent of net assets		2.40%	1.41%	[2]
Money Market Funds | First American US Treasury Obligations Fund Class X | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, at cost		$ 1,095,625	$ 551,232	[2]
Investment owned, Percent of net assets		2.27%	1.53%	[2]
Investments
Investment futures contracts			$ 202,475
Investments | SIT RISING RATE ETF
Investment owned, at cost		$ 11,928,143	$ 5,528,693
Investment owned, Percent of net assets		99.90%	96.40%
Investments | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, at cost		$ 1,095,625	$ 551,232
Investment owned, Percent of net assets		25.40%	23.90%
Assets in Excess of Other Liabilities | SIT RISING RATE ETF
Investment owned Percent of other liabilities		0.10%	3.60%	[3]
Assets in Excess of Other Liabilities | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned Percent of other liabilities		74.60%	76.10%	[3]
Short-term Investments | SIT RISING RATE ETF
Investment owned, Percent of net assets		97.20%	93.10%
Short-term Investments | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Percent of net assets		0.00%	0.00%
Short-term Investments | U.S. Treasury 10 Year Note | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Percent of net assets	[1]		1.453%
Futures Contracts
Investment futures contracts			$ 1,866,980
Futures Contracts | Baltic Exchange Panamax T/C Average Shipping Route Index Expiring October 25, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			452,165
Futures Contracts | Baltic Exchange Panamax T/C Average Shipping Route Index Expiring November 29, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			400,085
Futures Contracts | Baltic Exchange Panamax T/C Average Shipping Route Index Expiring December 27, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			404,040
Futures Contracts | Baltic Exchange Supramax Average Shipping Route Expiring January 31, 2020 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			37,250
Futures Contracts | Baltic Exchange Supramax Average Shipping Route Expiring February 28, 2020 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			38,910
Futures Contracts | Baltic Exchange Supramax Average Shipping Route Expiring March 31, 2020 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			44,125
Futures Contracts | Baltic Capesize Time Charter Expiring October 25, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			245,520
Futures Contracts | Baltic Capesize Time Charter Expiring November 29, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			257,640
Futures Contracts | Baltic Capesize Time Charter Expiring December 27, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount			$ 300,390
Futures Contracts | Baltic Exchange Panamax T/C Average Shipping Route Index Due July 26, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		$ 489,015
Futures Contracts | Baltic Exchange Panamax T/C Average Shipping Route Index Due August 30, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		497,835
Futures Contracts | Baltic Exchange Panamax T/C Average Shipping Route Index Due September 27, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		495,945
Futures Contracts | Baltic Exchange Supramax T/C Average Shipping Route Expiring Due July 26, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		147,435
Futures Contracts | Baltic Exchange Supramax T/C Average Shipping Route Expiring Due August 30, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		158,250
Futures Contracts | Baltic Exchange Supramax T/C Average Shipping Route Expiring September 27, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		161,505
Futures Contracts | Baltic Capesize Time Charter Expiring July 26, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		732,680
Futures Contracts | Baltic Capesize Time Charter Expiring August 30, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		719,840
Futures Contracts | Baltic Capesize Time Charter Expiring September 27, 2019 | BREAKWAVE DRY BULK SHIPPING ETF
Investment owned, Principal amount		$ 723,160

[1] All or a portion of this security is held as collateral for futures contracts and written options.

[2] Annualized seven-day yield as of December 31, 2019

[3] $-0- and $1,866,980, respectively, of cash is pledged as collateral for futures contracts