[Line Items] for Schedule of Shareholders' Equity [Table]

No definition available.

Name:	aaon_ScheduleOfShareholdersEquityLineItems
Namespace Prefix:	aaon_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

+ Details

Name:	us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_TreasuryStockSharesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_TreasuryStockValueAcquiredCostMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DividendsAxis=us-gaap_DividendDeclaredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=aaon_A2010StockRepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=aaon_A2005401kStockRepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=aaon_A2006DirectorandOfficerRepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stockholders' Equity (Details) - USD ($)				3 Months Ended		6 Months Ended		97 Months Ended	140 Months Ended	156 Months Ended
Stockholders' Equity (Details) - USD ($)	May 18, 2018	Nov. 07, 2017	May 16, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2018	May 15, 2018	Jun. 02, 2016	May 24, 2016	May 19, 2015
Schedule of Shareholders' Equity [Line Items]
Stock repurchased during period (in shares)						358,682	296,885			12,671,710
Aggregate price of shares repurchased since inception						$ 12,346,574	$ 10,433,710			$ 172,925,527
Average price of shares repurchased since inception (per share)						$ 34.42	$ 35.14			$ 13.65
Cash dividends declared per common share:				$ 0.16	$ 0.13	$ 0.16	$ 0.13
Dividend Declared
Schedule of Shareholders' Equity [Line Items]
Cash dividends declared per common share:	$ 0.16	$ 0.13	$ 0.13
2010 Stock Repurchase Program
Schedule of Shareholders' Equity [Line Items]
Stock repurchase program amount authorized (in shares)												2,000,000.0		5,700,000.0
Stock repurchase program, authorized amount											$ 15,000,000.0	$ 25,000,000.0	$ 25,000,000.0
Stock repurchased during period (in shares)						104,155	8,676	3,947,650
Aggregate price of shares repurchased since inception						$ 3,427,879	$ 283,654	$ 64,659,994
Average price of shares repurchased since inception (per share)						$ 32.91	$ 32.69	$ 16.38
2005 401(k) Stock Repurchase Program
Schedule of Shareholders' Equity [Line Items]
Stock repurchased during period (in shares)						231,387	258,051			6,781,410
Aggregate price of shares repurchased since inception						$ 8,108,190	$ 9,083,606			$ 90,176,995
Average price of shares repurchased since inception (per share)						$ 35.04	$ 35.20			$ 13.30
2006 Director and Officer Repurchase Program
Schedule of Shareholders' Equity [Line Items]
Stock repurchased during period (in shares)						23,140	30,158		1,942,650
Aggregate price of shares repurchased since inception						$ 810,505	$ 1,066,450		$ 18,088,538
Average price of shares repurchased since inception (per share)						$ 35.03	$ 35.36		$ 9.31