GENERAL AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Table Text Block]

Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives less an estimated salvage value, which are as follows:



Aircraft and related flight equipment:
Boeing 737 and Airbus 319/320 aircraft	20-25 years
Bombardier Q400 aircraft	15 years
Buildings	25 - 30 years
Minor building and land improvements	10 years
Capitalized leases and leasehold improvements	Generally shorter of lease term or estimated useful life
Computer hardware and software	3-10 years
Other furniture and equipment	5-10 years

Salvage values used for aircraft are 10% of the fair value, but as aircraft near the end of their useful lives, management updates the salvage value estimates based on current market conditions and expected use of the aircraft. “Related flight equipment” includes rotable and repairable spare inventories, which are depreciated over the associated fleet life unless otherwise noted.

Liabilities from Mileage Plan [Table Text Block]

Frequent flyer program deferred revenue and liabilities included in the consolidated balance sheets (in millions):



	2016		2015
Current Liabilities:
Other accrued liabilities	$	484	$	368
Other Liabilities and Credits:
Deferred revenue	638		427
Other liabilities	21		19
Total	$	1,143	$	814

Revenue from Mileage Plan [Table Text Block]

Frequent flyer program revenue included in the consolidated statements of operations (in millions):



	2016		2015		2014
Passenger revenues	$	293	$	267	$	246
Other—net revenues	429		329		295
Total frequent flyer program revenues	$	722	$	596	$	541