Note 8, Stock Based Compensation (Details) - USD ($) | 3 Months Ended | 9 Months Ended | |
Jun. 30, 2017 | Dec. 31, 2016 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016 | Sep. 30, 2016 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares | 236,034 | | | 236,034 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 44.60 | | | $ 44.60 | | $ 0 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Intrinsic Value, Amount Per Share | | | | | | 0 |
Share-based Compensation | $ 11,000,000 | | $ 14,000,000 | $ 33,000,000 | $ 20,000,000 | |
Adient Share Bifurcation | | | | 1 | | |
JCI Share Bifurcation | | | | 10 | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options | 0 | | | $ 0 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price | | | | 1 year 1 month 6 days | | |
Former Parent Outstanding Remaining Contractual Life | | | | 4 years 10 months 24 days | | |
Former Parent Outstanding Aggregate Intrinsic Value | 16,000,000 | | | $ 16,000,000 | | |
Adient Outstanding Remaining Contractual Life | | | | 4 years 1 month 6 days | | |
Adient Outstanding Aggregate Intrinsic Value | 7,000,000 | | | $ 7,000,000 | | |
Former Parent Exercisable Remaining Contractual Life | | | | 4 years 2 months 12 days | | |
Former Parent Exercisable Aggregate Intrinsic Value | 16,000,000 | | | $ 16,000,000 | | |
Adient Exercisable Remaining Contractual Life | | | | 3 years 7 months 6 days | | |
Adient Exercisable Aggregate Intrinsic Value | $ 6,000,000 | | | $ 6,000,000 | | |
Employee Stock Option [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price | $ 35.65 | | | $ 35.65 | | $ 32.42 |
Weighted Average Price Exercised Prior to 10.31.2016 | | $ 27.22 | | | | |
Weighted Average Options Forfeited prior to 10.31.2016 | | 31.71 | | | | |
Weighted Average Options Converted Prior to 10.31.2016 | | 33.28 | | | | |
Weighted Average Options Converted at Separation | | $ 32.49 | | | | |
Options Forfeited prior to 10.31.2016 | | 3,330 | | | | |
Options Converted Prior to 10.31.2016 | | 169,125 | | | | |
optionsconvertedatseparation | | 2,495,543 | | | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options | | | | | | 2,336,028 |
Adient Weighted Average Exercisable | $ 31.90 | | | $ 31.90 | | |
Adient Weighted Average Outstanding | $ 33.67 | | | $ 33.67 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 1,569,726 | | | 1,569,726 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price | $ 29.67 | | | $ 29.67 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price | | | | 4 years 9 months 18 days | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $ 23,000,000 | | | $ 23,000,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares | | | | 3,083 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Number of Shares, Period Increase (Decrease) | | | | (922,734) | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price | | | | $ 26.10 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | | 0 | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price | | | | $ 27.13 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options | 1,298,785 | | | 1,298,785 | | |
Options Exercised Prior to 10.31.2016 | | 6,280 | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | | | | $ 0 | | |
Former Parent Weighted Average Outstanding | $ 35.97 | | | $ 35.97 | | |
formerparentoptionsoutstanding | 1,354,043 | | | 1,354,043 | | |
Adientoutstandingoptions | 215,683 | | | 215,683 | | |
Former Parent Weighted Average Exercisable | $ 29.28 | | | $ 29.28 | | |
formerparentoptionsexercisable | 1,107,731 | | | 1,107,731 | | |
adientoptionsexercisable | 191,054 | | | 191,054 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term | | | | 4 years 1 month 6 days | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value | $ 22,000,000 | | | $ 22,000,000 | | |
Restricted Stock [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | | | | $ 45.19 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 2,289,306 | | | 2,289,306 | | 1,320,448 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | | (1,162,213) | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Intrinsic Value, Amount Per Share | $ 63,000,000 | | | $ 63,000,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 45.46 | | | $ 45.46 | | $ 46.42 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | | | | $ 50.30 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares | | | | 281,084 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period | | | | (47,297) | | |
Adientoutstandingoptions | 1,257,334 | | | 1,257,334 | | |
Weighted Average Options Converted Prior to 10.31.2016 | | $ 48.06 | | | | |
Options Converted Prior to 10.31.2016 | | 135,026 | | | | |
Weighted Average Options Converted at Separation | | | | $ 46.57 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | | | | $ 44.65 | | |
optionsconvertedatseparation | | | | 1,455,474 | | |
Former Parent Weighted Average Remaining Contractual Term | $ 45.57 | | | $ 45.57 | | |
formerparentoptionsoutstanding | 1,031,972 | | | 1,031,972 | | |
Adient Weighted Average Remaining Contractual Term | $ 45.41 | | | $ 45.41 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price | | | | 2 years 1 month 6 days | | |
Stock Appreciation Rights (SARs) [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | | | | $ 0 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 631,914 | | | 631,914 | | 654,694 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | | 0 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 31.29 | | | $ 31.29 | | $ 31.26 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested | $ 631,914 | | | $ 631,914 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | | | | $ 31.20 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period | | | | (4,757) | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Exercisable | $ 27.95 | | | $ 27.95 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Exercisable | 594,610 | | | 594,610 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Exercisble Remaining Contractual Term | | | | 3 years 6 months | | |
Former Parent Weighted Average Exercisable | $ 27.61 | | | $ 27.61 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price | | | | 3 years 8 months 12 days | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding | $ 11,000,000 | | | $ 11,000,000 | | |
formerparentoptionsexercisable | 537,786 | | | 537,786 | | |
Former Parent Exercisable Remaining Contractual Life | | | | 3 years 6 months | | |
Former Parent Exercisable Aggregate Intrinsic Value | $ 8,000,000 | | | $ 8,000,000 | | |
Adient Weighted Average Exercisable | $ 31.11 | | | $ 31.11 | | |
adientoptionsexercisable | 56,824 | | | 56,824 | | |
Adient Exercisable Remaining Contractual Life | | | | 3 years 6 months | | |
Adient Exercisable Aggregate Intrinsic Value | $ 2,000,000 | | | $ 2,000,000 | | |
Adient Outstanding Remaining Contractual Life | | | | 3 years 9 months 18 days | | |
Adient Outstanding Aggregate Intrinsic Value | $ 2,000,000 | | | $ 2,000,000 | | |
Weighted Average Price Exercised Prior to 10.31.2016 | | $ 29.68 | | | | |
Options Exercised Prior to 10.31.2016 | | (9,470) | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Number of Shares, Period Increase (Decrease) | | | | (50,266) | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | | | | $ 48.32 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options | 594,610 | | | 594,610 | | |
Former Parent Outstanding Remaining Contractual Life | | | | 3 years 8 months 12 days | | |
Former Parent Outstanding Aggregate Intrinsic Value | $ 9,000,000 | | | $ 9,000,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value | 10,000,000 | | | 10,000,000 | | |
SARS Weighted Average Options Converted Prior to 10.31.2016 | | $ 33.16 | | | | |
SARS Converted Prior to 10.31.2016 | | 41,713 | | | | |
SARS Weighted Average Options Converted at Separation | | $ 31.40 | | | | |
SARSconvertedatseparation | | 686,937 | | | | |
SARS Former Parent Weighted Average Outstanding | $ 31.22 | | | $ 31.22 | | |
SARS formerparentoptionsoutstanding | 571,699 | | | 571,699 | | |
SARS Adient Weighted Average Outstanding | $ 32.01 | | | $ 32.01 | | |
SARS Adientoutstandingoptions | 60,215 | | | 60,215 | | |
Performance Shares [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | | | | $ 44.60 | | |
PSU Weighted Average Price Converted 10.31.2016 | | $ 0 | | | | |
PSU converted 10.31.2016 | | 0 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | | | 236,034 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | | | | $ 0 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares | | | | 0 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period | | | | 0 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | | | | $ 0 | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options | $ 17,000,000 | | | $ 17,000,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price | | | | 2 years 4 months 24 days | | |