Debt	6 Months Ended
Jun. 30, 2017
Debt Disclosure [Abstract]
Debt	Debt Notes During the six months ended June 30, 2017, CAD 375 million ($283 million at June 30, 2017 rates) 4.76% Senior Notes due March 2018 were classified as Short-term debt and current portion of long-term debt in the Consolidated Statements of Financial Position as the date of maturity is less than one year. Revolving Credit Facilities As of June 30, 2017, Aon plc had one primary committed credit facility outstanding: its $900 million multi-currency U.S. credit facility expiring in February 2021 (the “2021 Facility”). The Company’s $400 million U.S. credit facility expired in March 2017. The 2021 Facility includes customary representations, warranties and covenants, including financial covenants that require Aon plc to maintain specified ratios of adjusted consolidated earnings before interest, taxes, depreciation, and amortization (“EBITDA”) to consolidated interest expense and consolidated debt to adjusted consolidated EBITDA, in each case, tested quarterly. At June 30, 2017, Aon plc did not have borrowings under the 2021 Facility, and was in compliance with all covenants contained therein during the six months ended June 30, 2017. Commercial Paper Aon Corporation, a wholly-owned subsidiary of Aon plc, has established a U.S. commercial paper program and a European multi-currency commercial paper program (the “CP Programs”). Commercial paper may be issued in an aggregate principal amount of up to $1.3 billion under the CP Programs, allocated between the two programs as determined by management, not to exceed the amount of committed credit, currently $900 million. The U.S. commercial paper program is fully and unconditionally guaranteed by Aon plc and the European commercial paper program is fully and unconditionally guaranteed by Aon Corporation. In the aggregate, the Company had no commercial paper outstanding at June 30, 2017 and $329 million of commercial paper outstanding at December 31, 2016, which is included in Short-term debt and current portion of long-term debt in the Company’s Condensed Consolidated Statements of Financial Position. The weighted average commercial paper outstanding for the three and six months ended June 30, 2017 was $318 million and $342 million, respectively. The weighted average commercial paper outstanding for the three and six months ended June 30, 2016 was $304 million and $240 million, respectively. The weighted average interest rate of the commercial paper outstanding for the three and six months ended June 30, 2017 was 0.26% and 0.18%, respectively. The weighted average interest rate of the commercial paper outstanding for the three and six months ended June 30, 2016 was 0.59% and 0.41% , respectively.

Debt

Notes

During the six months ended June 30, 2017, CAD 375 million ($283 million at June 30, 2017 rates) 4.76% Senior Notes due March 2018 were classified as Short-term debt and current portion of long-term debt in the Consolidated Statements of Financial Position as the date of maturity is less than one year.

Revolving Credit Facilities

As of June 30, 2017, Aon plc had one primary committed credit facility outstanding: its $900 million multi-currency U.S. credit facility expiring in February 2021 (the “2021 Facility”). The Company’s $400 million U.S. credit facility expired in March 2017.

The 2021 Facility includes customary representations, warranties and covenants, including financial covenants that require Aon plc to maintain specified ratios of adjusted consolidated earnings before interest, taxes, depreciation, and amortization (“EBITDA”) to consolidated interest expense and consolidated debt to adjusted consolidated EBITDA, in each case, tested quarterly. At June 30, 2017, Aon plc did not have borrowings under the 2021 Facility, and was in compliance with all covenants contained therein during the six months ended June 30, 2017.

Commercial Paper

Aon Corporation, a wholly-owned subsidiary of Aon plc, has established a U.S. commercial paper program and a European multi-currency commercial paper program (the “CP Programs”). Commercial paper may be issued in an aggregate principal amount of up to $1.3 billion under the CP Programs, allocated between the two programs as determined by management, not to exceed the amount of committed credit, currently $900 million. The U.S. commercial paper program is fully and unconditionally guaranteed by Aon plc and the European commercial paper program is fully and unconditionally guaranteed by Aon Corporation. In the aggregate, the Company had no commercial paper outstanding at June 30, 2017 and $329 million of commercial paper outstanding at December 31, 2016, which is included in Short-term debt and current portion of long-term debt in the Company’s Condensed Consolidated Statements of Financial Position. The weighted average commercial paper outstanding for the three and six months ended June 30, 2017 was $318 million and $342 million, respectively. The weighted average commercial paper outstanding for the three and six months ended June 30, 2016 was $304 million and $240 million, respectively. The weighted average interest rate of the commercial paper outstanding for the three and six months ended June 30, 2017 was 0.26% and 0.18%, respectively. The weighted average interest rate of the commercial paper outstanding for the three and six months ended June 30, 2016 was 0.59% and 0.41% , respectively.