[12][13] His portfolio included taxation, financial relations with lower governments, state ownership of Holland Casino and Nederlandse Loterij [nl], and Domains Movable Property.
[14] Idsinga was tasked with steering the 2025 Tax Plan, part of the overall budget, through the parliament, including the Senate where the governing coalition lacked a majority.
His savings, valued at over €6 million in 2023, were managed by a foundation for the duration of his term, and Idsinga refused to provide more visibility, citing his privacy.
[17] The NOS reported that he was eligible for major tax incentives for a 2019 investment in an algaculture company, which he had disclosed, by categorizing himself as an entrepreneur rather than an investor.
[20] Idsinga was succeeded by Tjebbe van Oostenbruggen two weeks later, and finance minister Eelco Heinen took over the defense of the 2025 Tax Plan.
He had been encouraged to reenter parliament by the parliamentary leader, Pieter Omtzigt, and his acting counterpart, Nicolien van Vroonhoven.