NW Holdings Balance Sheet (Unaudited) Statement $ in Thousands	Sep. 30, 2018 USD ($) shares
Cash and cash equivalents	$ 29,965
Total current assets	218,159
Total assets	3,081,407
Common stock - no par value; authorized 100,000,000 shares; 100 issued and outstanding at September 30, 2018	455,499
Total equity	$ 737,581
Common Stock, Shares Authorized | shares	100,000,000
Common Stock, Shares, Issued | shares	28,844,000
Common Stock, Shares, Outstanding | shares	28,844,000
Northwest Natural Holding Company [Member]
Cash and cash equivalents	$ 20,000
Total current assets	20,000
Total assets	20,000
Common stock - no par value; authorized 100,000,000 shares; 100 issued and outstanding at September 30, 2018	20,000
Total equity	$ 20,000
Common Stock, Shares Authorized | shares	100,000,000
Common Stock, Shares, Issued | shares	100
Common Stock, Shares, Outstanding | shares	100