EMPLOYEE BENEFIT PLANS (Details) (Predecessor [Member], USD $)	12 Months Ended									1 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 ONEOK Pension Plans [Member]	Dec. 31, 2012 ONEOK Pension Plans [Member]	Dec. 31, 2011 ONEOK Pension Plans [Member]	Dec. 31, 2013 ONEOK Postretirement Benefit Plans [Member]	Dec. 31, 2012 ONEOK Postretirement Benefit Plans [Member]	Dec. 31, 2011 ONEOK Postretirement Benefit Plans [Member]	Jan. 31, 2014 ONE Gas Pension and Postretirement Benefit Plans [Member]	Dec. 31, 2013 ONEOK 401(k) Plan [Member]	Dec. 31, 2012 ONEOK 401(k) Plan [Member]	Dec. 31, 2011 ONEOK 401(k) Plan [Member]	Dec. 31, 2013 ONEOK Profit-Sharing Plan [Member]	Dec. 31, 2012 ONEOK Profit-Sharing Plan [Member]	Dec. 31, 2011 ONEOK Profit-Sharing Plan [Member]
Employee Benefit Plans [Line Items]
Net periodic benefit cost				$ 35,000,000	$ 22,800,000	$ 18,900,000	$ 12,300,000	$ 16,600,000	$ 17,200,000
Profit sharing contribution percentage														1.00%
Maximum percentage of each participants eligible compensation subject to certain limits matching (in hundredths)											6.00%
Percent of employee contributions matched of eligible compensation (in hundredths)											100.00%
Expense charged to us by ONEOK, Inc.											8,300,000	8,400,000	8,500,000	1,600,000	2,100,000	2,100,000
Expected long-term return on plan assets	8.25%	8.25%	8.25%
Discount rate				4.25%	5.00%	5.50%	4.00%	5.00%	5.50%
Rate of compensation increase - minimum	3.45%	3.20%	3.30%
Rate of compensation increase - maximum	3.50%	3.80%	3.90%
Minimum number of years of service for certain employees to be eligible to participate in shared welfare plans that provide postretirement medical and life insurance benefits							5
Benefit obligation										1,100,000,000
Fair value of plan assets										1,000,000,000
Increase in deferred income taxes as a result of the transfer of unrecognized losses from ONEOK										86,000,000
Increase in regulatory assets as a result of the transfer of unrecognized losses from ONEOK										$ 331,000,000