table of contents the following table presents certain payments due by the company under contractual obligations with minimum firm commitments as of september 28 , 2013 and excludes amounts already recorded on the consolidated balance sheet , except for long-term debt ( in millions ) : lease commitments the company 2019s major facility leases are typically for terms not exceeding 10 years and generally provide renewal options for terms not exceeding five additional years . leases for retail space are for terms ranging from five to 20 years , the majority of which are for 10 years , and often contain multi-year renewal options . as of september 28 , 2013 , the company 2019s total future minimum lease payments under noncancelable operating leases were $ 4.7 billion , of which $ 3.5 billion related to leases for retail space . purchase commitments with outsourcing partners and component suppliers the company utilizes several outsourcing partners to manufacture sub-assemblies for the company 2019s products and to perform final assembly and testing of finished products . these outsourcing partners acquire components and build product based on demand information supplied by the company , which typically covers periods up to 150 days . the company also obtains individual components for its products from a wide variety of individual suppliers . consistent with industry practice , the company acquires components through a combination of purchase orders , supplier contracts , and open orders based on projected demand information . where appropriate , the purchases are applied to inventory component prepayments that are outstanding with the respective supplier . as of september 28 , 2013 , the company had outstanding off-balance sheet third- party manufacturing commitments and component purchase commitments of $ 18.6 billion . other obligations in addition to the off-balance sheet commitments mentioned above , the company had outstanding obligations of $ 1.3 billion as of september 28 , 2013 , that consisted mainly of commitments to acquire capital assets , including product tooling and manufacturing process equipment , and commitments related to advertising , research and development , internet and telecommunications services and other obligations . the company 2019s other non-current liabilities in the consolidated balance sheets consist primarily of deferred tax liabilities , gross unrecognized tax benefits and the related gross interest and penalties . as of september 28 , 2013 , the company had non-current deferred tax liabilities of $ 16.5 billion . additionally , as of september 28 , 2013 , the company had gross unrecognized tax benefits of $ 2.7 billion and an additional $ 590 million for gross interest and penalties classified as non-current liabilities . at this time , the company is unable to make a reasonably reliable estimate of the timing of payments in individual years in connection with these tax liabilities ; therefore , such amounts are not included in the above contractual obligation table . indemnification the company generally does not indemnify end-users of its operating system and application software against legal claims that the software infringes third-party intellectual property rights . other agreements entered into by payments due in than 1 payments due in payments due in payments due in than 5 years total .

 | payments due in less than1 year | payments due in 1-3 years | payments due in 4-5 years | payments due in more than5 years | total
long-term debt | $ 0 | $ 2500 | $ 6000 | $ 8500 | $ 17000
operating leases | 610 | 1200 | 1056 | 1855 | 4721
purchase obligations | 18616 | 0 | 0 | 0 | 18616
other obligations | 1081 | 248 | 16 | 3 | 1348
total | $ 20307 | $ 3948 | $ 7072 | $ 10358 | $ 41685

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Question: as of september 28 , 2013 , the company had non-current deferred tax liabilities of $ 16.5 billion . what was the difference between this and the balance of gross unrecognized tax benefits , in billions?
Program: subtract(16.5, 2.7)
Answer: 13.8