SkyWest (SKYW) 10-K 18 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 12, 2020	Jun. 28, 2019
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	0-14719
Entity Registrant Name	SKYWEST INC
Entity Incorporation, State or Country Code	UT
Entity Tax Identification Number	87-0292166
Entity Address, Address Line One	444 South River Road
Entity Address, City or Town	St. George
Entity Address, State or Province	UT
Entity Address, Postal Zip Code	84790
City Area Code	435
Local Phone Number	634-3000
Title of 12(b) Security	Common Stock, No Par Value
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 3,157,616,762
Trading Symbol	SKYW
Entity Common Stock, Shares Outstanding		50,474,289
Entity Central Index Key	0000793733
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 87,206	$ 328,384
Marketable securities	432,966	360,945
Income tax receivable	11,141	25,936
Receivables, net	82,977	64,194
Inventories, net	110,503	127,690
Prepaid aircraft rents		87,031
Other current assets	35,553	26,614
Total current assets	760,346	1,020,794
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	7,078,801	6,433,916
Deposits on aircraft	48,858	42,012
Buildings and ground equipment	265,398	291,544
Total property and equipment, gross	7,393,057	6,767,472
Less-accumulated depreciation and amortization	(1,998,376)	(1,761,728)
Total property and equipment, net	5,394,681	5,005,744
OTHER ASSETS
Operating lease right-of-use assets	336,009
Long-term prepaid assets		181,830
Other long-term assets	166,093	104,844
Total other assets	502,102	286,674
Total assets	6,657,129	6,313,212
CURRENT LIABILITIES:
Current maturities of long-term debt	364,126	350,206
Accounts payable	284,473	331,982
Accrued salaries, wages and benefits	133,856	161,606
Current maturities of operating lease liabilities	94,806
Taxes other than income taxes	15,004	16,024
Other current liabilities	32,411	65,008
Total current liabilities	924,676	924,826
LONG-TERM DEBT, net of current maturities	2,628,989	2,809,768
DEFERRED INCOME TAXES PAYABLE	623,580	518,159
DEFERRED AIRCRAFT CREDITS		29,308
NONCURRENT OPERATING LEASE LIABILITIES	259,237
OTHER LONG-TERM LIABILITIES	45,633	66,870
COMMITMENTS AND CONTINGENCIES (Note 5)
STOCKHOLDERS' EQUITY:
Preferred stock, 5,000,000 shares authorized; none issued
Common stock, no par value, 120,000,000 shares authorized; 81,742,937 and 81,239,289 shares issued, respectively	686,806	690,910
Retained earnings	2,079,179	1,776,585
Treasury stock, at cost, 31,420,179 and 29,850,999 shares, respectively	(590,971)	(503,182)
Accumulated other comprehensive loss		(32)
Total stockholders' equity	2,175,014	1,964,281
Total liabilities and stockholders' equity	$ 6,657,129	$ 6,313,212

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
CONSOLIDATED BALANCE SHEETS
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	81,742,937	81,239,289
Treasury stock, at cost, shares	31,420,179	29,850,999

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING REVENUES:
Total operating revenues	$ 2,971,963	$ 3,221,679	$ 3,122,592
OPERATING EXPENSES:
Salaries, wages and benefits	1,001,746	1,201,518	1,192,067
Depreciation and amortization	368,098	334,589	292,768
Special items	21,869
Other operating expenses	243,729	272,826	250,778
Total operating expenses	2,459,705	2,747,399	2,734,393
OPERATING INCOME	512,258	474,280	388,199
OTHER INCOME (EXPENSE):
Interest income	14,131	8,823	4,509
Interest expense	(127,755)	(120,409)	(104,925)
Other, net	47,671	3,620	400
Total other expense, net	(65,953)	(107,966)	(100,016)
INCOME BEFORE INCOME TAXES	446,305	366,314	288,183
PROVISION (BENEFIT) FOR INCOME TAXES	106,206	85,942	(140,724)
NET INCOME	$ 340,099	$ 280,372	$ 428,907
BASIC EARNINGS PER SHARE (in dollars per share)	$ 6.68	$ 5.40	$ 8.28
DILUTED EARNINGS PER SHARE (in dollars per share)	$ 6.62	$ 5.30	$ 8.08
Weighted average common shares:
Basic (in shares)	50,932,000	51,914,000	51,804,000
Diluted (in shares)	51,375,000	52,871,000	53,100,000
COMPREHENSIVE INCOME:
Net income	$ 340,099	$ 280,372	$ 428,907
Net unrealized appreciation on marketable securities, net of taxes	32	18	21
TOTAL COMPREHENSIVE INCOME	340,131	280,390	428,928
Flying agreements
OPERATING REVENUES:
Total operating revenues	2,889,265	3,169,520	3,078,297
Airport customer service and other
OPERATING REVENUES:
Total operating revenues	82,698	52,159	44,295
Aircraft maintenance, materials and repairs
OPERATING EXPENSES:
Total operating expenses	514,313	556,259	579,463
Aircraft fuel
OPERATING EXPENSES:
Total operating expenses	119,115	117,657	85,136
Airport related expenses
OPERATING EXPENSES:
Total operating expenses	118,837	109,605	118,374
Aircraft rentals
OPERATING EXPENSES:
Total operating expenses	$ 71,998	$ 154,945	$ 215,807

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Dec. 31, 2016	$ 657,353	$ 1,103,751	$ (410,090)	$ (71)	$ 1,350,943
Balance (in shares) at Dec. 31, 2016	79,781		(28,015)
Increase (Decrease) in Stockholders' Equity
Net income		428,907			428,907
Net unrealized appreciation on marketable securities, net of taxes				21	21
Exercise of common stock options and stock issued under equity award plan	$ 1,658				1,658
Exercise of common stock options and stock issued under equity award plan (in shares)	529
Treasury shares acquired from vested employee stock awards for income tax withholdings			$ (5,080)		(5,080)
Treasury shares acquired from vested employee stock awards for income tax withholdings (in shares)			(145)
Sale of common stock under employee stock purchase plan	$ 3,002				3,002
Sale of common stock under employee stock purchase plan (in shares)	88
Stock based compensation expense related to the issuance of equity awards	$ 10,580				10,580
Impact of adoption of ASU 2016-09 (See Note 1) | Accounting Standards Update 2016-09		867			867
Treasury stock purchases			$ (20,008)		(20,008)
Treasury stock purchases (in shares)			(484)
Cash dividends declared		(16,568)			(16,568)
Balance at Dec. 31, 2017	$ 672,593	1,516,957	$ (435,178)	(50)	1,754,322
Balance (in shares) at Dec. 31, 2017	80,398		(28,644)
Increase (Decrease) in Stockholders' Equity
Net income		280,372			280,372
Net unrealized appreciation on marketable securities, net of taxes				18	18
Exercise of common stock options and stock issued under equity award plan	$ 2,174				2,174
Exercise of common stock options and stock issued under equity award plan (in shares)	780
Treasury shares acquired from vested employee stock awards for income tax withholdings			$ (13,556)		(13,556)
Treasury shares acquired from vested employee stock awards for income tax withholdings (in shares)			(239)
Sale of common stock under employee stock purchase plan	$ 3,038				3,038
Sale of common stock under employee stock purchase plan (in shares)	61
Stock based compensation expense related to the issuance of equity awards	$ 13,105				13,105
Treasury stock purchases			$ (54,448)		(54,448)
Treasury stock purchases (in shares)			(968)
Cash dividends declared		(20,744)			(20,744)
Balance at Dec. 31, 2018	$ 690,910	1,776,585	$ (503,182)	(32)	1,964,281
Balance (in shares) at Dec. 31, 2018	81,239		(29,851)
Increase (Decrease) in Stockholders' Equity
Change in accounting principle and other (see Note 6) | Accounting Standards Update 2016-02		(13,141)			(13,141)
Balance, as adjusted		1,763,444			1,951,140
Net income		340,099			340,099
Net unrealized appreciation on marketable securities, net of taxes				$ 32	32
Exercise of common stock options and stock issued under equity award plan	$ 3,106				3,106
Exercise of common stock options and stock issued under equity award plan (in shares)	707
Treasury shares acquired from vested employee stock awards for income tax withholdings			$ (9,313)		(9,313)
Treasury shares acquired from vested employee stock awards for income tax withholdings (in shares)			(173)
Sale of common stock under employee stock purchase plan	$ 3,165				3,165
Sale of common stock under employee stock purchase plan (in shares)	65
Stock based compensation expense related to the issuance of equity awards	$ 5,770				5,770
Common stock purchased and cancelled	$ (16,145)				(16,145)
Common stock purchased and cancelled (in shares)	(268)
Treasury stock purchases			$ (78,476)		(78,476)
Treasury stock purchases (in shares)			(1,396)
Cash dividends declared		(24,364)			(24,364)
Balance at Dec. 31, 2019	$ 686,806	$ 2,079,179	$ (590,971)		$ 2,175,014
Balance (in shares) at Dec. 31, 2019	81,743		(31,420)

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
Net unrealized appreciation on marketable securities, tax	$ 10	$ 6	$ 7
Cash dividends declared (in dollars per share)	$ 0.48	$ 0.40	$ 0.32

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 340,099	$ 280,372	$ 428,907
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	368,098	334,589	292,768
Stock based compensation expense	10,274	13,105	10,580
Gain on sale of subsidiary	(46,525)
Special items	21,869
Net increase (decrease) in deferred income taxes	109,654	99,139	(145,517)
Changes in operating assets and liabilities:
Decrease in restricted cash			8,243
Decrease (increase) in receivables	(40,700)	(21,464)	4,201
Decrease (increase) in income tax receivable	14,795	(20,620)	1,673
Increase in inventories	(4,303)	(7,935)	(1,246)
Decrease in other current assets	2,707	77,484	26,017
Increase in operating lease right-of-use asset	(895)
Decrease in deferred aircraft credits		(14,243)	(8,520)
Increase (decrease) in accounts payable and other current liabilities	(54,043)	62,107	67,018
NET CASH PROVIDED BY OPERATING ACTIVITIES	721,030	802,534	684,124
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(1,938,750)	(2,308,768)	(1,533,867)
Sales of marketable securities	1,866,761	2,451,344	1,440,283
Net cash received from sale of subsidiary	53,200
Acquisition of property and equipment:
Aircraft and rotable spare parts	(581,329)	(1,062,380)	(661,176)
Buildings and ground equipment	(80,586)	(34,397)	(27,467)
Proceeds from the sale of aircraft, property and equipment	26,008		51,994
Deposits on aircraft	(52,817)	(41,937)	(46,733)
Return of deposits applied towards acquired aircraft	46,346	49,550	36,533
Decrease (increase) in other assets	4,133	(36,816)	(10,904)
NET CASH USED IN INVESTING ACTIVITIES	(657,034)	(983,404)	(751,337)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of long-term debt	200,040	784,665	471,677
Principal payments on long-term debt	(382,442)	(370,775)	(330,258)
Proceeds from issuance of common stock	6,271	5,212	4,660
Purchase of treasury stock	(78,476)	(54,448)	(20,008)
Purchase of common stock	(16,145)
Employee income tax paid on vested equity awards	(9,313)	(13,556)	(5,080)
Increase in debt issuance cost	(1,642)	(3,892)	(3,737)
Payment of cash dividends	(23,467)	(19,744)	(15,015)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(305,174)	327,462	102,239
Increase (decrease) in cash and cash equivalents	(241,178)	146,592	35,026
Cash and cash equivalents at beginning of period	328,384	181,792	146,766
CASH AND CASH EQUIVALENTS AT END OF PERIOD	87,206	328,384	181,792
Non-cash investing activities:
Acquisition of rotable spare parts	16,514	367	755
Debt assumed on aircraft acquired under operating leases	14,475	59,132
Engines contributed to joint venture	22,313
Non-cash assets used to acquire aircraft under operating leases	153,566
Lease liability arising from the recognition of right-of-use asset	456,472
Cash paid during the period for:
Interest, net of capitalized amounts	131,733	118,268	105,639
Income taxes	2,490	$ 2,661	$ 5,010
SUPPLEMENTAL DISCLOSURE OF SALE OF SUBSIDIARY:
Decrease in carrying amount of assets	(101,448)
Decrease in carrying amount of liabilities	68,341
Cash received from buyers	79,632
Gain on sale of subsidiary	$ 46,525

Nature of Operations and Summar

Nature of Operations and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Nature of Operations and Summary of Significant Accounting Policies
Nature of Operations and Summary of Significant Accounting Policies	(1) Nature of Operations and Summary of Significant Accounting Policies SkyWest, Inc. (the “Company”), through its subsidiary, SkyWest Airlines, Inc. (“SkyWest Airlines”) operates the largest regional airline in the United States. On January 22, 2019, the Company completed the sale of its former wholly owned subsidiary, ExpressJet Airlines, Inc. (“ExpressJet”). As of December 31, 2019, SkyWest Airlines offered scheduled passenger service under code-share agreements with Delta, United, American and Alaska with approximately 2,300 total daily departures to destinations in the United States, Canada, Mexico and the Caribbean. Additionally, the Company provides airport customer service and ground handling services for other airlines throughout its system. As of December 31, 2019, the Company had 483 aircraft in scheduled service out of a combined fleet of 544 aircraft consisting of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CRJ200 CRJ700 CRJ900 E175 Total Delta 84 ​ 13 ​ 43 ​ 59 ​ 199 ​ United 99 ​ 19 ​ — ​ 65 ​ 183 ​ American 7 ​ 62 ​ — ​ — ​ 69 ​ Alaska — ​ — ​ — ​ 32 ​ 32 ​ Aircraft in scheduled service ​ 190 ​ 94 ​ 43 ​ 156 ​ 483 ​ Subleased to an un-affiliated entity 4 ​ 10 ​ 5 ​ — ​ 19 ​ Other* 20 ​ 22 ​ — ​ — ​ 42 ​ Total Fleet 214 ​ 126 ​ 48 ​ 156 ​ 544 ​ *As of December 31, 2019, these aircraft have been removed from service and are in the process of being placed under a leasing arrangement with a third party, are aircraft transitioning between code-share agreements with the Company’s major airline partners and being used as a supplemental spare aircraft, or are in the process of being parted out. SkyWest Airlines has been a code-share partner with Delta since 1987, United since 1997, Alaska since 2011 and American since 2012. As of December 31, 2019, SkyWest Airlines operated as a Delta Connection carrier primarily in Salt Lake City and Minneapolis, a United Express carrier primarily in Los Angeles, San Francisco, Denver, Houston, Chicago and the Pacific Northwest, an American carrier primarily in Chicago, Los Angeles and Phoenix and an Alaska carrier primarily in the Pacific Northwest. SkyWest Airlines operates the following aircraft manufactured by Bombardier Aerospace (“Bombardier”): CRJ200s, CRJ700s and CRJ900s, and E175s manufactured by Embraer S.A. (“Embraer”). The CRJ200 is a single-class 50-seat aircraft. The CRJ700, CRJ900 E175 have seat Basis of Presentation The Company’s consolidated financial statements include the accounts of the Company and the SkyWest Airlines, ExpressJet (for the periods owned by the Company) and SkyWest Leasing segments, with all inter-company transactions and balances having been eliminated. In preparing the accompanying consolidated financial statements, the Company has reviewed, as determined necessary by the Company’s management, events that have occurred after December 31, 2019, through the filing date of the Company’s annual report with the U.S. Securities and Exchange Commission. The Company reclassified certain prior period amounts to conform to the current period presentation (see Recent Accounting Pronouncements). Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less to be cash equivalents. The Company had no restricted cash as of December 31, 2019 and 2018. Marketable Securities The Company’s investments in debt securities are classified as available-for-sale and are reported at fair market value with the net unrealized appreciation reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. At the time of sale, any realized appreciation or depreciation, calculated by the specific identification method, is recognized in other income and expense. At December 31, 2019, the fair market value of the available-for-sale securities was the amortized cost. The Company’s position in marketable securities as of December 31, 2019 and 2018 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross unrealized ​ Gross unrealized ​ ​ ​ ​ At December 31, 2019 Amortized Cost holding gains holding losses Fair market value Total cash and cash equivalents ​ $ 87,206 ​ $ — ​ $ — ​ $ 87,206 ​ Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bond and bond funds ​ $ 267,243 ​ $ — ​ $ — ​ $ 267,243 ​ Commercial Paper ​ 165,723 ​ — ​ — ​ 165,723 ​ Total marketable securities ​ $ 432,966 ​ $ — ​ $ — ​ $ 432,966 ​ Total assets measured at fair value ​ $ 520,172 ​ $ — ​ $ — ​ $ 520,172 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross unrealized ​ Gross unrealized ​ ​ ​ ​ At December 31, 2018 Amortized Cost holding gains holding losses Fair market value Total cash and cash equivalents ​ $ 328,384 ​ $ — ​ $ — ​ $ 328,384 ​ Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bond and bond funds ​ $ 229,825 ​ $ — ​ $ (42) ​ $ 229,783 ​ Commercial Paper ​ 131,163 ​ — ​ (1) ​ 131,162 ​ Total marketable securities ​ $ 360,988 ​ $ — ​ $ (43) ​ $ 360,945 ​ Total assets measured at fair value ​ $ 689,372 ​ $ — ​ $ (43) ​ $ 689,329 ​ ​ Inventories Inventories include expendable parts, fuel and supplies and are valued at cost (FIFO basis) less an allowance for obsolescence based on historical results, excess parts and management’s expectations of future operations. Expendable inventory parts are charged to expense as used. An obsolescence allowance for flight equipment expendable parts is accrued based on estimated lives of the corresponding fleet types and salvage values. The inventory allowance as of December 31, 2019 and 2018 was $15.9 million and $22.1 million, respectively. Property and Equipment Property and equipment are stated at cost and depreciated over their useful lives to their estimated residual values using the straight-line method as follows: ​ ​ ​ Assets ​ Depreciable Life ​ Current Residual Value ​ Aircraft, rotable spares, and spare engines ​ up to 22 years up to 20 % ​ Ground equipment ​ up to 10 years 0 % ​ Office equipment ​ up to 7 years ​ 0 % ​ Leasehold improvements ​ Shorter of 15 years or lease term 0 % ​ Buildings ​ 20 - 39.5 years 0 % ​ ​ Impairment of Long-Lived Assets As of December 31, 2019, the Company had approximately $5.4 billion of property and equipment and related assets. In accounting for these long-lived and intangible assets, the Company makes estimates about the expected useful lives of the assets, the expected residual values of certain of these assets, and the potential for impairment based on the fair value of the assets and the cash flows they generate. Factors indicating potential impairment include, but are not limited to, significant decreases in the market value of the long-lived assets, a significant change in the condition of the long-lived assets and operating cash flow losses associated with the use of the long-lived assets. On a periodic basis, the Company evaluates whether impairment indicators are present. When considering whether or not impairment of long- lived assets exists, the Company groups similar assets together at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities and compare the undiscounted cash flows for each asset group to the net carrying amount of the assets supporting the asset group. Asset groupings are done at the fleet or contract level. The Company did not recognize any impairment charges of long-lived assets during the years ended December 31, 2019, 2018 and 2017. Capitalized Interest Interest is capitalized on aircraft purchase deposits as a portion of the cost of the asset and is depreciated over the estimated useful life of the asset. During the years ended December 31, 2019, 2018 and 2017, the Company capitalized interest costs of approximately $1.6 million, $1.5 million, and $1.4 million, respectively. Maintenance The Company operates under a U.S. Federal Aviation Administration approved continuous inspection and maintenance program. The Company uses the direct expense method of accounting for its regional jet engine overhauls wherein the expense is recorded when the overhaul event occurs. The Company has engine services agreements with third-party vendors to provide long-term engine services covering the scheduled and unscheduled repairs for most of its aircraft. Under the terms of the agreements, the Company pays a fixed dollar amount per engine hour flown on a monthly basis and the third-party vendors will assume the responsibility to repair the engines at no additional cost to the Company, subject to certain specified exclusions. Maintenance costs under these contracts are recognized when the engine hour is flown pursuant to the terms of each contract. The costs of maintenance for airframe and avionics components, landing gear and other recurring maintenance are expensed as incurred. Flying Agreements and Airport Customer Service and Other Revenues The Company recognizes flying agreements revenue and airport customer service and other revenues when the service is provided under its code-share agreements. Under the Company’s fixed-fee arrangements (referred to as “fixed-fee arrangements,” “fixed-fee contracts” or “capacity purchase agreements”) with Delta Air Lines, Inc. (“Delta”), United Airlines, Inc. (“United”), American Airlines, Inc. (“American”) and Alaska Airlines, Inc. (“Alaska”) (each, a “major airline partner”), the major airline partner generally pays the Company a fixed-fee for each departure, flight hour (measured from takeoff to landing, excluding taxi time) or block hour (measured from takeoff to landing, including taxi time) incurred, and an amount per aircraft in service each month with additional incentives based on flight completion and on-time performance. The major airline partner also directly pays for or reimburses the Company for certain direct expenses incurred under the fixed-fee arrangement, such as fuel, airport landing fees and airport rents. Under the fixed-fee arrangements, the Company’s performance obligation is met and revenue is recognized when each flight is completed and is reflected in flying agreements revenue. The transaction price for the fixed-fee agreements is determined from the fixed-fee consideration, incentive consideration and directly reimbursed expenses earned as flights are completed over the agreement term. For the year ended December 31, 2019, fixed-fee arrangements represented approximately Under the Company’s revenue-sharing arrangements (referred to as a “revenue-sharing” or “prorate” arrangement), the major airline partner and the Company negotiate a passenger fare proration formula, pursuant to which the Company receives a percentage of the ticket revenues for those passengers traveling for one portion of their trip on a Company airline and the other portion of their trip on the major airline partner. Under the Company’s prorate flying agreements, the performance obligation is met and revenue is recognized when each flight is completed based upon the portion of the prorate passenger fare the Company anticipates that it will receive for each completed flight. The transaction price for the prorate agreements is determined from the proration formula derived from each passenger ticket amount on each completed flight over the agreement term. For the year ended December 31, 2019, prorate flying arrangements represented approximately Airport customer service and other revenues primarily consist of ground handling functions, such as gate and ramp agent services at applicable airports where the Company provides such services. The transaction price for airport customer service agreements is determined from an agreed-upon rate by location applied to the applicable number of flights handled by the Company over the agreement term. Additionally, airport customer service and other revenues includes revenue generated from aircraft and spare engines leased to third parties. Of the Company’s $5.4 billion of property and equipment, net as of December 31, 2019, $97.0 million of regional jet aircraft and spare engines was leased to third parties under operating leases. The Company mitigates the residual asset risks of these assets by leasing aircraft and engine types that can be operated by the Company in the event of a default. A portion of the Company’s leases to third parties contain variable payments from lessees based on departures where the Company pays for maintenance. Additionally, the operating leases typically have specified lease return condition requirements paid by the lessee to the Company and the Company typically maintains inspection rights under the leases. ​ The following table represents the Company’s airport customer service and other revenue for the years ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2019 2018 2017 Airport customer service revenue ​ $ 45,538 ​ $ 48,236 ​ $ 41,002 Operating lease income relating to lease payments ​ 27,552 ​ 3,923 ​ 3,293 Operating lease income relating to variable lease payments ​ 9,608 ​ — ​ — Airport customer service and other ​ $ 82,698 ​ $ 52,159 ​ $ 44,295 ​ ​ ​ The following table summarizes future minimum rental income under operating leases primarily related to leased aircraft that had remaining non-cancelable lease terms as of December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 $ 32,724 2021 ​ 31,344 ​ 2022 ​ 24,786 ​ 2023 ​ 18,530 ​ 2024 ​ 18,222 ​ Thereafter ​ 54,932 ​ ​ ​ $ 180,538 ​ ​ Other ancillary revenues commonly associated with airlines, such as baggage fee revenue, ticket change fee revenue and the marketing component of the sale of mileage credits, are retained by the Company’s major airline partners on flights that the Company operates under its code-share agreements. ​ The following table represents the Company’s flying agreements revenue by type for the years ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2019 2018 2017 Capacity purchase agreements revenue: flight operations ​ $ 1,538,062 ​ $ 1,856,253 ​ $ 1,805,510 Capacity purchase agreements revenue: aircraft lease ​ 830,247 ​ 814,518 ​ 834,366 Prorate agreements revenue ​ 520,956 ​ 498,749 ​ 438,421 Flying agreements revenue ​ $ 2,889,265 ​ $ 3,169,520 ​ $ 3,078,297 ​ A portion of the Company’s compensation under its fixed-fee agreements is designed to reimburse the Company for certain aircraft ownership costs. The consideration for aircraft ownership costs varies by agreement but is intended to cover either the Company’s aircraft principal and interest debt service costs, its aircraft depreciation and interest expense or its aircraft lease expense costs while the aircraft is under contract. The consideration received for the use of the aircraft under the Company’s fixed-fee agreements is reflected as lease revenue, inasmuch as the agreements identify the “right of use” of a specific type and number of aircraft over a stated period of time. The lease revenue associated with the Company’s fixed-fee agreements is accounted for as an operating lease and is reflected as flying agreements revenue on the Company’s consolidated statements of comprehensive income. The Company has not separately stated aircraft rental income and aircraft rental expense in the consolidated statement of comprehensive income since the use of the aircraft is not a separate activity of the total service provided. The Company’s fixed-fee and prorate agreements include weekly provisional cash payments from the respective major airline partner based on a projected level of flying each month. The Company and each major airline partner subsequently reconcile these payments to the actual completed flight activity on a monthly or quarterly basis. ​ In the event a flying agreement includes a mid-term rate reset to adjust rates prospectively and the contractual rates under the Company’s flying agreements have not been finalized at quarterly or annual financial statement dates, the Company applies the variable constraint guidance under Topic 606, where the Company records revenue to the extent it believes that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. ​ In several of the Company’s agreements, the Company is eligible to receive incentive compensation upon the achievement of certain performance criteria. The incentives are defined in the agreements and are measured and determined on a monthly, quarterly or semi-annual basis. At the end of each period during the term of an agreement, the Company calculates the incentives achieved during that period and recognizes revenue attributable to that agreement accordingly, subject to the variable constraint guidance under Topic 606. The following summarizes the significant provisions of each code-share agreement the Company has with each major airline partner through SkyWest Airlines: Delta Connection Agreements Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates Delta Connection Agreement (fixed-fee arrangement) ​ ● CRJ 200 ● CRJ 700 ● CRJ 900 ● E175 ​ 55 13 43 59 ​ ● Individual aircraft have scheduled removal dates from 2020 to 2029 ● ​ Delta Connection Prorate Agreement (revenue-sharing arrangement) ​ ● CRJ 200 ​ 29 ​ ● Terminable with 30-day ​ ​ United Express Agreements ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates United Express Agreements (fixed-fee arrangement) ​ ● CRJ 200 ● CRJ 700 ● E175 ​ 68 19 65 ​ ​ ● Individual aircraft have scheduled removal dates under the agreement between 2020 and 2029 ● ​ United Express Prorate Agreement (revenue-sharing arrangement) ​ ● CRJ 200 ​ ​ 31 ​ ● Terminable with 120-day ​ ​ American Agreements ​ ​ ​ ​ ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates American Agreement (fixed-fee arrangement) ​ ● CRJ 700 ​ ​ 62 ​ ● ● ​ American Prorate Agreement (revenue-sharing arrangement) ​ ● ​ 7 ​ ● 120-day ​ ​ Alaska Capacity Purchase Agreement ​ ​ ​ ​ ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates Alaska Agreement (fixed-fee arrangement) ​ ● E175 ​ ​ 32 ​ ● ● ​ ​ In addition to the contractual arrangements described above, SkyWest Airlines has entered into fixed-fee agreements with Delta and American to place additional E175 aircraft into service. As of December 31, 2019, the Company was scheduled to take delivery of new E175 aircraft in connection with its agreement with American. The delivery dates for the new E175 aircraft are currently scheduled to be completed by the end of 2021. Final delivery dates may be adjusted based on various factors. Additionally, the Company is scheduled to add an additional six used E175 aircraft under the Delta agreement during 2020. ​ SkyWest Airlines also entered into an agreement with Delta to place one CRJ900 aircraft under a nine-year fixed-fee agreement in 2020. ​ SkyWest Airlines also entered into an agreement with American to place ten used CRJ700s under a multi-year contract. As of December 31, 2019, SkyWest Airlines had placed two of these CRJ700 aircraft into service with American. When an aircraft is scheduled to be removed from a fixed-fee arrangement, the Company may, as practical under the circumstances, negotiate an extension with the respective major airline partner, negotiate the placement of the aircraft with another major airline partner, return the aircraft to the lessor if the aircraft is leased and the lease is expiring, place owned aircraft for sale, or pursue other uses for the aircraft. Other uses for the aircraft may include placing the aircraft in a prorate arrangement, leasing the aircraft to a third party or parting out the aircraft to use the engines and parts as spare inventory or to lease the engines to a third party. ​ Airport customer service and other revenues primarily consist of ground handling functions, such as gate and ramp agent services at applicable airports where the Company provides such services. The transaction price for airport service agreements is determined from an agreed-upon rate by location applied to the applicable number of flights handled (measured by departures) by the Company over the agreement term. ​ The Company’s operating revenues could be impacted by a number of factors, including changes to the Company’s code-share agreements with its major airline partners, changes in flight schedules, contract modifications resulting from contract renegotiations, the Company’s ability to earn incentive payments contemplated under the Company’s code-share agreements and settlement of reimbursement disputes with the Company’s major airline partners. ​ As of December 31, 2019, the Company had $83.0 million in accounts receivable of which $58.8 million related to flying agreements. As of December 31, 2018, the Company had $64.2 million in accounts receivable of which $52.7 million related to flying agreements. ​ Income Taxes The Company recognizes a net liability or asset for the deferred tax consequences of all temporary differences between the tax basis of assets and liabilities and their reported amounts in the consolidated financial statements that are expected to result in taxable or deductible amounts in future years when the reported amounts of the assets and liabilities are recovered or settled. Net Income Per Common Share Basic net income per common share (“Basic EPS”) excludes dilution and is computed by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per common share (“Diluted EPS”) reflects the potential dilution that could occur if stock options or other contracts to issue common stock were exercised or converted into common stock. The computation of Diluted EPS does not assume exercise or conversion of securities that would have an anti-dilutive effect on net income (loss) per common share. During the year ended December 31, 2019, 150,000 performance share units (at target performance) were excluded in the computation of Diluted EPS since the Company had not achieved the minimum target thresholds as of December 31, 2019. During the year ended December 31, 2018, 207,000 performance share units (at target performance) were excluded in the computation of Diluted EPS since the Company had not achieved the minimum target thresholds as of December 31, 2018. During the year ended December 31, 2017, 284,000 performance share units (at target performance) were excluded in the computation of Diluted EPS since the Company had not achieved the minimum target thresholds as of December 31, 2017. The calculation of the weighted average number of common shares outstanding for Basic EPS and Diluted EPS are as follows for the years ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Numerator: ​ ​ ​ ​ Net Income ​ $ 340,099 ​ $ 280,372 ​ $ 428,907 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share weighted average shares ​ 50,932 ​ 51,914 ​ 51,804 ​ Dilution due to stock options and restricted stock units ​ 443 ​ 957 ​ 1,296 ​ Diluted earnings per share weighted average shares ​ 51,375 ​ 52,871 ​ 53,100 ​ Basic earnings per share ​ $ 6.68 ​ $ 5.40 ​ $ 8.28 ​ Diluted earnings per share ​ $ 6.62 ​ $ 5.30 ​ $ 8.08 ​ ​ Comprehensive Income (Loss) Comprehensive income (loss) includes charges and credits to stockholders’ equity that are not the result of transactions with the Company’s shareholders, including changes in unrealized appreciation on marketable debt securities. Fair Value of Financial Instruments The carrying amounts reported in the consolidated balance sheets for receivables and accounts payable approximate fair values because of the immediate or short-term maturity of these financial instruments. Marketable securities are reported at fair value based on market quoted prices in the consolidated balance sheets. If quoted prices in active markets are no longer available, the Company has estimated the fair values of these securities utilizing a discounted cash flow analysis. These analyses consider, among other items, the collateralization underlying the security investments, the creditworthiness of the counterparty, the timing of expected future cash flows, and the expectation of the next time the security is expected to have a successful auction. The fair value of the Company’s long-term debt is estimated based on current rates offered to the Company for similar debt and was approximately $3,049.1 million as of December 31, 2019, as compared to the carrying amount of $3,017.5 million as of December 31, 2019. The Company’s fair value of long-term debt as of December 31, 2018 was $3,157.3 million as compared to the carrying amount of $3,185.4 million as of December 31, 2018. Segment Reporting Generally accepted accounting principles require disclosures related to components of a company for which separate financial information is available to, and regularly evaluated by, the Company’s chief operating decision maker when deciding how to allocate resources and in assessing performance. The Company’s three operating segments (prior to the sale of ExpressJet in January 2019) consist of the operations conducted by SkyWest Airlines, ExpressJet (for the periods owned by the Company) and SkyWest Leasing. Following the sale of ExpressJet, the Company has two reportable segments: SkyWest Airlines and SkyWest Leasing. Information pertaining to the Company’s reportable segments is presented in Note 2, Segment Reporting ​ Recent Accounting Pronouncements ​ Standards Effective in Future Years and Not Yet Adopted In June 2016, the Financial Accounting Standards Board (the “FASB”) issued ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments” (“Topic 326”), which requires measurement and recognition of expected credit losses for financial assets held and requires enhanced disclosure regarding significant estimates and judgments used in estimating credit losses. Topic 326 is effective for the Company beginning January 1, 2020. The Company will adopt Topic 326, on January 1, 2020. The Company’s primary financial assets as of December 31, 2019, include trade receivables from its flying agreements, notes and other receivables from third parties. The Company estimates it will record a credit loss amount between Recently Adopted Standards In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (“Topic 842”). Topic 842 and subsequently issued amendments require certain leases with durations longer than 12 months to be recognized on the balance sheet. The Company adopted Topic 842 effective January 1, 2019 and elected the package of transition practical expedients for expired or existing contracts, which does not require reassessment of: (1) whether any of the Company’s contracts are or contain leases, (2) lease classification and (3) initial direct costs. In July 2018, the FASB issued ASU No. 2018-11, “Targeted Improvements - Leases (Topic 842).” This update provides an optional transition method that allows entities to elect to apply the standard using the modified retrospective approach at its effective date, versus recasting the prior years presented. If this adoption method is elected, an entity would recognize a cumulative-effect adjustment to the opening balance of retained earnings in the year of adoption. The Company elected this adoption method and recognized a cumulative-effect adjustment to the opening balance of retained earnings on January 1, 2019. ​ Additionally, the Company’s adoption of Topic 842 did not have a significant impact on the recognition, measurement or presentation of lease revenue and lease expenses within the condensed consolidated statements of operations and comprehensive income or the condensed consolidated statements of cash flows. The Company’s adoption of Topic 842 did not have a material impact on the timing or amount of the Company’s lease revenue as a lessor. The Company’s prepaid aircraft rents, accrued aircraft rents and deferred rent credits that were separately stated in the Company’s December 31, 2018 balance sheet have been classified as a component of the Company’s right-of-use assets effective January 1, 2019. The consolidated financial statements for 2019 are presented under the new standard, while comparative years presented are not adjusted and continue to be reported in accordance with the Company’s historical accounting policy. ​ See Note 6, " Leases

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2019
Segment Reporting
Segment Reporting	(2) Segment Reporting Generally accepted accounting principles require disclosures related to components of a company for which separate financial information is available to, and regularly evaluated by, the Company’s chief operating decision maker when deciding how to allocate resources and in assessing performance. Prior to the Company’s sale of ExpressJet on January 22, 2019, the Company’s three reporting segments consisted of the operations of SkyWest Airlines, ExpressJet and SkyWest Leasing activities. The segment information presented for ExpressJet reflects the period of time prior to the sale, when ExpressJet was operating as a subsidiary of the Company. ​ The Company’s chief operating decision maker analyzes the profitability of operating new aircraft financed through the issuance of debt, including the Company’s E175 fleet, separately from the profitability of the Company’s capital deployed for ownership and financing of such aircraft. The SkyWest Airlines segment includes revenue earned under the applicable fixed-fee contracts attributed to operating such aircraft and the respective operating costs. The SkyWest Leasing segment includes applicable revenue earned under the applicable fixed-fee contracts attributed to the ownership of new aircraft acquired through the issuance of debt and the respective depreciation and interest expense of such aircraft. The SkyWest Leasing segment also includes the activity of leasing regional jet aircraft and spare engines to third parties. The SkyWest Leasing segment’s total assets and capital expenditures include new aircraft acquired through the issuance of debt and assets leased to third parties. ​ The following represents the Company’s segment data for the years ended December 31, 2019, 2018 and 2017 (in thousands). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 ​ ​ ​ SkyWest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Airlines ​ ​ ExpressJet ​ ​ SkyWest Leasing ​ ​ Consolidated Operating revenues ​ $ 2,478,681 ​ $ 24,050 ​ $ 469,232 ​ $ 2,971,963 ​ Operating expense ​ 2,214,632 ​ ​ 28,690 ​ ​ 216,383 ​ 2,459,705 ​ Depreciation and amortization expense ​ 168,246 ​ 971 ​ 198,881 ​ 368,098 ​ Special items ​ ​ 18,508 ​ ​ 3,361 ​ ​ — ​ ​ 21,869 ​ Interest expense ​ 13,525 ​ — ​ 114,230 ​ 127,755 ​ Segment profit (loss) (1) ​ 250,524 ​ (4,640) ​ 138,619 ​ 384,503 ​ Total assets ​ 2,728,964 ​ — ​ 3,928,165 ​ 6,657,129 ​ Capital expenditures (including non-cash) ​ 270,191 ​ — ​ 576,279 ​ 846,470 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2018 ​ ​ ​ SkyWest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Airlines ​ ​ ExpressJet ​ ​ SkyWest Leasing ​ ​ Consolidated Operating revenues ​ $ 2,346,251 ​ $ 564,202 ​ $ 311,226 ​ $ 3,221,679 ​ Operating expense ​ 2,022,560 ​ ​ 577,608 ​ ​ 147,231 ​ 2,747,399 ​ Depreciation and amortization expense ​ 155,511 ​ 37,290 ​ 141,788 ​ 334,589 ​ Interest expense ​ 17,021 ​ 2,340 ​ 101,048 ​ 120,409 ​ Segment profit (loss) (1) ​ 306,670 ​ (15,746) ​ 62,947 ​ 353,871 ​ Total assets ​ 2,531,707 ​ 279,303 ​ 3,502,202 ​ 6,313,212 ​ Capital expenditures (including non-cash) ​ 149,731 ​ 10,137 ​ 996,408 ​ 1,156,276 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2017 ​ ​ ​ ​ SkyWest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Airlines ​ ​ ExpressJet ​ ​ SkyWest Leasing ​ ​ Consolidated Operating revenues ​ $ 2,092,368 ​ $ 790,282 ​ $ 239,942 ​ $ 3,122,592 ​ Operating expense ​ 1,807,540 ​ ​ 818,683 ​ ​ 108,170 ​ ​ 2,734,393 ​ Depreciation and amortization expense ​ 134,563 ​ 51,982 ​ 106,223 ​ ​ 292,768 ​ Interest expense ​ 21,544 ​ 4,127 ​ 79,254 ​ ​ 104,925 ​ Segment profit (loss) (1) ​ 263,284 ​ (32,528) ​ 52,518 ​ 283,274 ​ Identifiable intangible assets, other than goodwill ​ — ​ ​ 4,896 ​ ​ — ​ ​ 4,896 ​ Total assets ​ 2,245,051 ​ ​ 599,122 ​ ​ 2,630,227 ​ ​ 5,474,400 ​ Capital expenditures (including non-cash) ​ 124,955 ​ 14,278 ​ 550,165 ​ 689,398 ​ (1) Segment profit is operating income less interest expense ​

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2019
Long-Term Debt
Long-Term Debt	(3) Long-term Debt Long-term debt consisted of the following as of December 31, 2019 and 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2019 ​ 2018 Notes payable to banks, due in semi-annual installments, variable interest based on LIBOR, or with an interest rate of 4.00% through 2019, secured by aircraft ​ $ — ​ $ 6,429 ​ Notes payable to a financing company, due in semi-annual installments, with a fixed interest rate of 3.25% through 2021, secured by aircraft ​ 18,412 ​ 36,324 ​ Notes payable to banks, due in semi-annual installments plus interest at 6.10% to 6.51% through 2021, secured by aircraft ​ 22,557 ​ 41,592 ​ Notes payable to banks, due in monthly installments, plus interest at 1.95% to 6.86% through 2029, secured by aircraft ​ 438,878 ​ 476,369 ​ Notes payable to banks, due in quarterly installments, plus interest at 3.39% to 5.08% through 2031, secured by aircraft ​ ​ 2,537,676 ​ ​ 2,621,416 ​ Notes payable to banks due in monthly installments, interest at 3.30% through 2019, secured by spare engines ​ — ​ 3,308 ​ Long-term debt ​ $ 3,017,523 ​ $ 3,185,438 ​ Current portion of long-term debt ​ (367,954) ​ (354,072) ​ Less long-term portion of unamortized debt issue cost, net ​ ​ (20,580) ​ ​ (21,598) ​ Long-term debt, net of current maturities and debt issue costs ​ $ 2,628,989 ​ $ 2,809,768 ​ ​ ​ ​ ​ ​ ​ ​ ​ Current portion of long-term debt ​ 367,954 ​ 354,072 ​ Less current portion of unamortized debt issue cost, net ​ ​ (3,828) ​ ​ (3,866) ​ Current portion of long-term debt, net of debt issue costs ​ $ 364,126 ​ $ 350,206 ​ ​ During the year ended December 31, 2019, the Company took delivery of ten E175 aircraft that the Company financed through $200.0 million of long-term debt. The debt associated with the ten E175 aircraft has a 12-year As of December 31, 2019 and 2018, the Company had $3.0 billion and $3.2 billion, respectively, of long-term debt obligations primarily related to the acquisition of aircraft and certain spare engines. The average effective interest rate on the debt related to those long-term debt obligations at December 31, 2019 and 2018, was approximately 4.2%. During the year ended December 31, 2019, the Company used $30.1 million in cash to extinguish $30.1 million in debt early. During the year ended December 31, 2018, the Company used $43.5 million in cash to extinguish $43.5 million in debt early. These payments did not result in a pre-tax gain or loss in the consolidated statements of comprehensive income. The aggregate amounts of principal maturities of long-term debt as of December 31, 2019 were as follows (in thousands): ​ ​ ​ ​ ​ 2020 $ 367,954 2021 ​ 352,005 ​ 2022 ​ 365,907 ​ 2023 ​ 374,906 ​ 2024 ​ 327,630 ​ Thereafter ​ 1,229,121 ​ ​ ​ $ 3,017,523 ​ ​ As of December 31, 2019 and 2018, SkyWest Airlines had a $75 million line of credit. The line of credit includes minimum liquidity and profitability covenants and is secured by certain assets. As of December 31, 2019, the Company was in compliance with the line of credit covenants. As of December 31, 2019 and 2018, SkyWest Airlines had no amount outstanding under the facility. However, at December 31, 2019 and 2018 the Company had $8.8 million and $9.7 million, respectively, in letters of credit issued under the facility which reduced the amount available under the facility to $66.2 million and $65.3 million, respectively. The facility expires on September 1, 2021 and has a variable interest rate of LIBOR plus 2.5% at December 31, 2019. As of December 31, 2019 and 2018, the Company had $61.7 million and $78.7 million, respectively, in letters of credit and surety bonds outstanding with various banks and surety institutions in addition to the letters of credit outstanding under the line of credit.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Taxes
Income Taxes	(4) Income Taxes The provision (benefit) for income taxes includes the following components (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Current tax provision (benefit): ​ ​ ​ ​ Federal ​ $ (4,395) ​ $ (21,598) ​ $ 5,853 ​ State ​ 891 ​ 1,465 ​ 180 ​ Foreign ​ ​ — ​ ​ 1,575 ​ ​ — ​ ​ ​ (3,504) ​ (18,558) ​ 6,033 ​ Deferred tax provision (benefit): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ 95,655 ​ 92,250 ​ (166,890) ​ State ​ 14,055 ​ 12,250 ​ 20,133 ​ ​ ​ 109,710 ​ 104,500 ​ (146,757) ​ Provision (benefit) for income taxes ​ $ 106,206 ​ $ 85,942 ​ $ (140,724) ​ ​ The following is a reconciliation between a federal income tax rate of 21% in 2019 and 2018 and 35% for 2017 of income before income taxes and the effective tax rate which is derived by dividing the provision (benefit) for income taxes by the income before the provision for income taxes (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Computed provision for income taxes at the statutory rate $ 93,724 $ 76,926 $ 100,864 ​ Increase (decrease) in income taxes resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ State income tax provision, net of federal income tax benefit ​ 15,645 ​ 12,711 ​ 7,778 ​ Non-deductible expenses ​ ​ 3,934 ​ ​ 1,956 ​ ​ 3,230 ​ Valuation allowance changes affecting the provision for income taxes ​ (517) ​ (1,187) ​ 505 ​ Foreign income taxes, net of federal & state benefit ​ ​ — ​ ​ 1,192 ​ ​ — ​ Excess tax benefits from share-based compensation ​ ​ (3,525) ​ ​ (4,548) ​ ​ (5,377) ​ Revaluation of net deferred taxes for the Tax Cuts and Jobs Act of 2017 ​ ​ — ​ ​ — ​ ​ (246,845) ​ Other, net ​ (3,055) ​ (1,108) ​ (879) ​ Provision (benefit) for income taxes ​ $ 106,206 ​ $ 85,942 ​ $ (140,724) ​ ​ For the year ended December 31, 2019, the Company released $0.5 million of valuation allowance against certain deferred tax assets primarily associated with ExpressJet state net operating losses. For the year ended December 31, 2018, the Company released million valuation allowance, respectively against certain deferred tax assets primarily associated with ExpressJet state net operating losses with a limited carry forward period and Company capital losses with a limited carry forward period. For the year ended December 31, 2017, the Company recorded million of valuation allowance against certain deferred tax assets primarily associated with ExpressJet state net operating losses. The decrease in the valuation allowance for 2019 was primarily based on changes in the Company's income tax projections which reduced the amount of deferred tax assets that are anticipated to expire before the deferred tax assets may be utilized. ​ The Company recorded a $3.5 million, $4.5 million and $5.4 million benefit from share-based compensation in 2019, 2018 and 2017, respectively, relating to ASU 2016-09 which, requires excess tax benefits and deficiencies to be recognized in the income tax provision during the period stock options are exercised and when stock awards vest. ​ The significant components of the Company’s net deferred tax assets and liabilities as of December 31, 2019 and 2018 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2019 ​ 2018 Deferred tax assets: ​ ​ ​ Accrued benefits ​ $ 20,848 ​ $ 32,462 ​ Net operating loss carryforward ​ 358,685 ​ 344,375 ​ AMT credit carryforward ​ 4,397 ​ 15,744 ​ Aircraft credits ​ 9,114 ​ 35,924 ​ Accrued reserves and other ​ 17,225 ​ 18,710 ​ Total deferred tax assets ​ 410,269 ​ 447,215 ​ Valuation allowance ​ (892) ​ (9,455) ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ Accelerated depreciation ​ (1,032,957) ​ (955,919) ​ Total deferred tax liabilities ​ (1,032,957) ​ (955,919) ​ Net deferred tax liability ​ $ (623,580) ​ $ (518,159) ​ ​ ​ The Company's valuation allowance is related to certain deferred tax assets with a limited carry forward period where the Company does not anticipate utilizing these deferred tax assets prior to the lapse of the carry forward period. The Company's AMT credit carryforward includes credits from prior acquisitions. ​ At %, respectively. The Company anticipated that the federal and state net operating losses will start to expire in 2030 and 2020, respectively. The Company has recorded a valuation allowance for state net operating losses the Company anticipates will expire before the benefit will be realized due to the limited carry forward periods. As of December 31, 2019 and 2018, the Company also had an alternative minimum tax credit of approximately $4.4 million and $8.8 million, respectively, which does not expire. Under the Tax Cuts and Jobs Act of 2017, the Company will realize the alternative minimum tax credit either by offsetting regular tax due or as a refundable credit over the next two years . The Company has no ongoing federal or state examinations. Federal tax years 2016, 2017 and 2018 are open to examination. ​ Under ASC Topic 740, the accounting guidance related to uncertainty in tax positions requires that the impact of a tax position be recognized in the financial statements if that position is more likely than not of being sustained on audit, based on the technical merits of the position. A reconciliation of the beginning and ending amount of unrecognized tax benefits for the year ended December 31, 2019 and 2018 is as follows (in thousands) : ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2019 2018 Unrecognized tax benefits at the beginning of year ​ $ 14,553 ​ $ 2,223 Gross increases - current year tax positions ​ ​ — ​ 13,899 ​ Gross increases - prior year tax positions ​ ​ 67 ​ — ​ Gross decreases - prior year tax positions ​ — ​ (1,569) ​ Unrecognized tax benefits at end of year ​ $ 14,620 ​ $ 14,553 ​ Interest and penalties in year-end balance ​ $ 67 ​ $ — ​ ​ For the year ending December 31, 2019, the Company has recorded $67,000 of interest expense related to uncertain tax positions not offset by the Company's tax attributes.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies
Commitments and Contingencies	(5) Commitments and Contingencies Self-Insurance The Company self-insures a portion of its potential losses from claims related to workers’ compensation, environmental issues, property damage, medical insurance for employees and general liability. Losses are accrued based on an estimate of the ultimate aggregate liability for claims incurred, using standard industry practices and the Company’s actual experience. The Company uses judgment and estimates in determining the ultimate aggregate liabilities for claims incurred in its workers’ compensation liability. The Company also used significant assumptions in determining the workers compensation liability such as an estimation of loss payment and loss reporting development patterns. At December 31, 2019 and 2018, the Company’s accrued workers’ compensation liability totaled $23.9 million and $42.0 million, respectively. Actual results could differ from these estimates. Legal Matters The Company is subject to certain legal actions which it considers routine to its business activities. As of December 31, 2019, management believed, after consultation with legal counsel, that the ultimate outcome of such legal matters was not likely to have a material adverse effect on the Company’s financial position, liquidity or results of operations. Concentration Risk and Significant Customers The Company requires no collateral from its major airline partners or customers, but monitors the financial condition of its major airline partners. Under the majority of the Company’s code-share agreements, the Company receives weekly payments from its major code-share partners that approximate a significant percentage of the compensation earned for such period. Additionally, the Company provides certain customer service functions at multiple airports for various airlines and the Company maintains an allowance for doubtful accounts receivable based upon expected collectability of all accounts receivable. The Company’s allowance for doubtful accounts totaled $18,000 and $158,000 as of December 31, 2019 and 2018, respectively. For the years ended December 31, 2019, 2018 and 2017, the Company’s contractual relationships with Delta and United combined accounted for approximately 77.6%, 81.4% and 82.9%, respectively of the Company’s total revenues. Employees Under Collective Bargaining Agreements As of December 31, 2019, the Company had approximately 13,700 full- time equivalent employees. Although

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases
Leases	(6) Leases Effective January 1, 2019, the Company adopted Topic 842. The Company leases property and equipment under operating leases. For leases with durations longer than 12 months, the Company recorded the related operating lease right-of-use asset and operating lease liability at the present value of lease payments over the term. The Company used its incremental borrowing rate to discount the ​ Aircraft During the first quarter of 2019, the Company acquired 52 CRJ aircraft under an early lease buyout arrangement with the lessor for $111.7 million. During the third quarter of 2019, the Company acquired four CRJ900 aircraft under an early lease buyout arrangement with the lessor for $30.0 million. ​ With the adoption of Topic 842, the Company evaluated whether leased aircraft asset groups within the Company’s fleet were impaired. Under the transition guidance for Topic 842, a company is permitted to recognize a previously unrecognized impairment related to a right-of-use asset in the period prior to the adoption date of Topic 842 if the event giving rise to the impairment occurred before the adoption date. In 2016, the Company recorded an impairment on certain of its long-lived assets, which included the Company’s CRJ200 aircraft . In 2016, the market lease rate was less than the contractual lease rate on the Company’s CRJ200 leased aircraft. The Company recorded an impairment of ​ Airport facilities The Company has operating leases for facility space including airport terminals, office space, cargo warehouses and maintenance facilities. The Company generally leases this space from government agencies that control the use of the airport. The remaining lease terms for facility space vary from one month to 37 years. The Company’s operating leases with lease rates that are variable based on airport operating costs, use of the facilities or other variable factors are excluded from the Company’s right-of-use assets and operating lease liabilities in accordance with accounting guidance. ​ Leases As of December 31, 2019, the Company’s right-of-use assets were $336.0 million, the Company’s current maturities of operating lease liabilities were $94.8 million, and the Company’s noncurrent lease liabilities were $259.2 million. During 2019, the Company paid $75.4 million in operating leases reflected as a reduction from operating cash flows. ​ The table below presents lease related terms and discount rates as of December 31, 2019. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2019 Weighted-average remaining lease term ​ Operating leases ​ ​ 6.84 years ​ Weighted-average discount rate ​ ​ ​ Operating leases ​ ​ 6.4% ​ ​ The Company’s lease costs for 2019 and 2018 included the following components (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2019 2018 Operating lease cost $ 104,011 $ 185,337 Variable and short-term lease cost ​ 5,232 ​ 5,143 Sublease income ​ ​ (1,436) ​ ​ — Total lease cost $ 107,807 $ 190,480 ​ property and equipment under non-cancelable operating leases, which are generally on a long-term, triple-net lease basis pursuant to which the Company pays taxes, maintenance, insurance and certain other operating expenses applicable to the leased property. The Company expects that, in the normal course of business, such operating leases that expire will be renewed or replaced by other leases, or the property may be purchased rather than leased. The following table summarizes future minimum rental payments primarily related to leased aircraft required under operating leases that had initial or remaining non-cancelable lease terms as of December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ 2020 $ 94,806 2021 ​ 84,285 ​ 2022 ​ 73,960 ​ 2023 ​ 68,581 ​ 2024 ​ 27,282 ​ Thereafter ​ 94,746 ​ ​ ​ $ 443,660 ​ ​ The majority of the Company’s leased aircraft are owned and leased through trusts whose sole purpose is to purchase, finance and lease these aircraft to the Company (“Leveraged Lease Agreements”). The Company is not a beneficiary of such trusts and the Company does not have an ownership interest in such trusts. The Company’s leveraged leases do not require the Company to guarantee a portion of the residual values of the leased assets held by the trust and the Company’s leveraged lease agreements do not contain a fixed purchase option or have any other terms that represent variable interests in such trusts. As a result, the Company has not consolidated any of these trusts. Total rental expense for non-cancelable aircraft operating leases was approximately $72.0 million, $154.9 million and $215.8 million for the years ended December 31, 2019, 2018 and 2017, respectively. The minimum rental expense for airport station rents was approximately $23.1 million, $19.6 million and $30.3 million for the years ended December 31, 2019, 2018 and 2017, respectively. Disclosures related to periods prior to the adoption of the New Lease Standard ​ ​ ​ ​ ​ ​ ​ 2019 $ 87,256 2020 ​ 101,741 ​ 2021 ​ 90,787 ​ 2022 ​ 72,593 ​ 2023 ​ 65,749 ​ Thereafter ​ 59,820 ​ ​ ​ $ 477,946 ​ ​

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Measurements
Fair Value Measurements	(7) Fair Value Measurements The Company holds certain assets that are required to be measured at fair value in accordance with GAAP. The Company determined fair value of these assets based on the following three levels of inputs: ​ Level 1 Level 2 Level 3 ​ As of December 31, 2019, the Company held certain assets that are required to be measured at fair value on a recurring basis. Assets measured at fair value on a recurring basis are summarized below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements as of December 31, 2019 ​ ​ Total Level 1 Level 2 Level 3 Marketable Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bonds and bond funds ​ $ 267,243 ​ $ — ​ $ 267,243 ​ $ — ​ Commercial paper ​ 165,723 ​ — ​ 165,723 ​ — ​ ​ ​ $ 432,966 ​ $ — ​ $ 432,966 ​ $ — ​ Cash, Cash Equivalents and Restricted Cash ​ ​ 87,206 ​ 87,206 ​ — ​ — ​ Total Assets Measured at Fair Value ​ $ 520,172 ​ $ 87,206 ​ $ 432,966 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements as of December 31, 2018 ​ ​ Total ​ Level 1 ​ Level 2 ​ Level 3 Marketable Securities ​ ​ ​ ​ ​ Bonds and bond funds ​ $ 229,783 ​ $ — ​ $ 229,783 ​ $ — ​ Commercial paper ​ 131,162 ​ — ​ 131,162 ​ — ​ ​ ​ $ 360,945 ​ $ — ​ $ 360,945 ​ $ — ​ Cash, Cash Equivalents and Restricted Cash ​ ​ 328,384 ​ 328,384 ​ — ​ — ​ Total Assets Measured at Fair Value ​ $ 689,329 ​ $ 328,384 ​ $ 360,945 ​ $ — ​ The Company’s “Marketable Securities” classified as Level 2 primarily utilize broker quotes in a non-active market for valuation of these securities. No significant transfers between Level 1, Level 2 and Level 3 occurred during the year ended December 31, 2019. The Company’s policy regarding the recording of transfers between levels is to record any such transfers at the end of the reporting period.

Special Items

Special Items	12 Months Ended
	Dec. 31, 2019
Special Items
Special Items	(8) Special Items The following table summarizes the components of the Company's special items, for the year ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2019 2018 2017 Special items: ​ ​ ​ ​ ​ ​ ​ ​ ​ Parts credit 1 ​ $ 18,508 ​ $ — ​ $ — Employee severance 2 ​ 3,361 ​ ​ — ​ — Total special items ​ $ 21,869 ​ $ — ​ $ — (1) The Company terminated an agreement with an aircraft manufacturer that obligated the Company to future aircraft lease return conditions on aircraft the Company leased. In conjunction with the terminated agreement, the aircraft manufacturer released the Company from the future aircraft lease return obligations and the Company agreed to terminate aircraft part credits previously issued by the manufacturer to the Company. As a result of the terminated agreement, the Company recorded a non-cash expense of $18.5 million (pre-tax) during 2019 to write-off the terminated aircraft part credits, which was reflected as a special items operating expense in the consolidated statement of comprehensive income. These special items are reflected in the SkyWest Airlines operating expenses under Note 2 Segment Reporting . ​ (2) During 2019, the Company incurred $3.4 million of employee severance related costs associated with the sale of ExpressJet that are also reflected in special items. These special items are reflected in the ExpressJet operating expenses under Note 2 Segment Reporting .

Capital Transactions

Capital Transactions	12 Months Ended
	Dec. 31, 2019
Capital Transactions
Capital Transactions	(9) Capital Transactions Preferred Stock The Company is authorized to issue 5,000,000 shares of preferred stock in one or more series without shareholder approval. No shares of preferred stock are presently outstanding. The Company’s Board of Directors is authorized, without any further action by the shareholders of the Company, to (i) divide the preferred stock into series; (ii) designate each such series; (iii) fix and determine dividend rights; (iv) determine the price, terms and conditions on which shares of preferred stock may be redeemed; (v) determine the amount payable to holders of preferred stock in the event of voluntary or involuntary liquidation; (vi) determine any sinking fund provisions; and (vii) establish any conversion privileges. Stock Compensation On May 7, 2019, the Company’s shareholders approved the adoption of the SkyWest, Inc. 2019 Long-Term Incentive Plan, which provides for the issuance of up to 4,500,000 shares of common stock to the Company’s directors, employees, consultants and advisors (the “2019 Incentive Plan”). The 2019 Incentive Plan provides for awards in the form of options to acquire shares of common stock, stock appreciation rights, restricted stock grants, restricted stock units and performance awards. The 2019 Incentive Plan is administered by the Compensation Committee of the Company’s Board of Directors (the “Compensation Committee”). As of December 31, 2019, the 2019 Incentive Plan had 4.4 million shares remaining available for future issuance. Stock Options The fair value of stock options awarded under the Company’s stock option plans has been estimated as of the grant date using the Black-Scholes option pricing model. The Company uses historical data to estimate option exercises and employee termination in the option pricing model. The expected term of options granted is derived from the output of the option pricing model and represents the period of time that options granted are expected to be outstanding. The expected volatilities are based on the historical volatility of the Company’s traded stock and other factors. During the years ended December 31, 2019, 2018 and 2017, the Company did not grant any options to purchase shares of common stock. Options are exercisable for a period as defined by the Compensation Committee on the date granted; however, no stock option will be exercisable before six months have elapsed from the date of grant and no stock option shall be exercisable after seven years from the date of grant. The following table summarizes the stock option activity for all of the Company’s plans for the years ended December 31, 2019, 2018 and 2017. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ 2018 ​ 2017 ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ Aggregate ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ Remaining ​ Intrinsic ​ ​ ​ Average ​ ​ ​ Average ​ ​ Number of ​ Exercise ​ Contractual ​ Value ​ Number of ​ Exercise ​ Number of ​ Exercise ​ ​ Options ​ Price ​ Term ​ ($000) ​ Options ​ Price ​ Options ​ Price Outstanding at beginning of year 300,580 ​ $ 13.70 3.0 years $ 9,249.4 458,103 $ 13.73 819,981 $ 13.58 ​ Granted — ​ — ​ ​ ​ ​ ​ — ​ — — ​ — ​ Exercised (232,514) ​ 13.36 ​ ​ ​ ​ ​ (157,523) ​ 13.80 (356,209) ​ 13.36 ​ Cancelled (7,835) ​ 15.86 ​ ​ ​ ​ ​ — ​ — (5,669) ​ 14.33 ​ Outstanding at end of year 60,231 ​ 14.74 3.1 years $ 3,005.1 300,580 ​ 13.70 458,103 ​ 13.73 ​ Exercisable at December 31, 2019 60,231 ​ ​ 14.74 ​ 3.1 years $ 3,005.1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exercisable at December 31, 2018 235,672 ​ ​ 13.36 ​ 2.7 years $ 7,330.7 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The total intrinsic value of options to acquire shares of the Company’s common stock that were exercised during the years ended December 31, 2019, 2018 and 2017 was $10.5 million, $7.1 million and $9.94 million, respectively. The following table summarizes the status of the Company’s non-vested stock options as of December 31, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ Number of ​ Grant-Date ​ ​ Shares ​ Fair Value Non-vested shares at beginning of year 64,908 ​ $ 5.32 ​ Granted — ​ ​ — ​ Vested (57,073) ​ 5.27 ​ Cancelled (7,835) ​ ​ 5.66 ​ Non-vested shares at end of year — ​ $ — ​ ​ The following table summarizes information about the Company’s stock options outstanding at December 31, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding ​ Options Exercisable ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ Remaining ​ Weighted Average ​ Number ​ Weighted Average Range of Exercise Prices ​ Outstanding ​ Contractual Life ​ Exercise Price ​ Exercisable ​ Exercise Price $13.00 to $13.99 2,034 2.1 years $ 13.51 ​ 2,034 $ 13.51 ​ $14.00 to $15.00 58,197 3.1 years ​ 14.78 58,197 ​ 14.78 ​ $13.00 to $15.00 60,231 3.1 years ​ $ 14.74 60,231 ​ $ 14.74 ​ ​ Restricted Stock Units During the year ended December 31, 2019, the Company granted 104,120 The following table summarizes the activity of restricted stock units granted to certain Company employees for the years ended December 31, 2019, 2018 and 2017: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ ​ Grant-Date Fair ​ ​ Number of RSUs ​ ​ Value Non-vested RSUs outstanding at December 31, 2016 926,931 ​ $ 13.65 ​ Granted 160,137 ​ 35.81 ​ Vested (230,903) ​ 12.01 ​ Cancelled (40,575) ​ 15.78 ​ Non-vested RSUs outstanding at December 31, 2017 815,590 ​ $ 18.35 ​ Granted 115,044 ​ 53.40 ​ Vested (330,580) ​ 13.57 ​ Cancelled (24,273) ​ 27.77 ​ Non-vested RSUs outstanding at December 31, 2018 575,781 ​ $ 27.71 ​ Granted 104,120 ​ 48.65 ​ Vested (251,853) ​ 14.79 ​ Cancelled (143,362) ​ 30.85 ​ Non-vested RSUs outstanding at December 31, 2019 284,686 ​ $ 45.21 ​ ​ Performance Stock Units During the year ended December 31, 2019, the Compensation Committee granted performance share units, which are performance based restricted stock units, to certain Company employees with three-year performance-based financial metrics that the Company must meet before those awards may be earned and the performance period is measured for the three years ending December 31, 2021. The Company’s compensation expense for performance share units is based upon the projected number of performance share units estimated to be awarded at the conclusion of the performance period. During 2019, the Compensation Committee awarded 67,853 additional shares of stock related to the performance share grant in 2016 based on the Company’s performance for the three years ended December 31, 2018 measured against the pre-established targets for the same period. The Compensation Committee will determine the achievement of performance results and corresponding vesting of performance shares for each year’s grant in 2017, 2018 and 2019 following the conclusion of the respective performance period. At the end of each performance period, the number of shares awarded can range from 0% to 200% of the original granted amount for performance share units granted in 2019, 2018 and 2017. The following table summarizes the activity of performance share units granted at target as of December 31, 2019. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ ​ Grant-Date ​ ​ Number of PSUs ​ ​ Fair Value Non-vested PSUs outstanding at December 31, 2016 363,993 ​ $ 14.23 Granted 119,315 ​ 35.81 Vested — ​ — Cancelled (14,732) ​ 15.00 Non-vested PSUs outstanding at December 31, 2017 468,576 ​ $ 19.70 Granted 90,264 ​ 53.41 Additional PSUs awarded from the 2015 grant 92,335 ​ 13.62 Vested (277,029) ​ 13.62 Cancelled (3,229) ​ 30.09 Non-vested PSUs outstanding at December 31, 2018 370,917 ​ $ 30.84 Granted 87,864 ​ 48.81 Additional PSUs awarded from the 2016 grant 67,853 ​ 14.80 Vested (203,582) ​ 14.80 Cancelled (89,481) ​ 34.70 Non-vested PSUs outstanding at December 31, 2019 233,571 ​ $ 45.44 ​ During the years ended December 31, 2019, 2018 and 2017 the Company granted fully-vested shares of common stock to the Company’s directors in the amounts of 18,576, 15,165 and 22,617 shares, respectively, with a weighted average grant-date fair value of $48.45, $53.40, and $35.81 respectively. During the year ended December 31, 2019, 2018 and 2017, the Company recorded equity-based compensation expense of $10.3 million, $13.1 million and $10.6 million, respectively. Additionally, the Company incurred $7.9 million of employee severance related costs associated with the sale of ExpressJet, partially offset by a forfeiture credit of $4.5 million, primarily resulting from stock-based compensation awards that terminated upon the sale of ExpressJet during 2019. As of December 31, 2019, the Company had $10.0 million of total unrecognized compensation cost related to non-vested restricted stock grants and non-vested performance stock units. Total unrecognized compensation cost will be adjusted for future changes in estimated forfeitures. The Company expects to recognize this cost over a weighted average period of 1.7 years. Taxes The Company’s treatment of stock option grants of non-qualified options, restricted stock units and performance shares results in the creation of a deferred tax asset, which is a temporary difference, until the time that the option is exercised or the restrictions lapse.

Retirement Plans and Employee S

Retirement Plans and Employee Stock Purchase Plans	12 Months Ended
	Dec. 31, 2019
Retirement Plans and Employee Stock Purchase Plans
Retirement Plans and Employee Stock Purchase Plans	(10) Retirement Plans and Employee Stock Purchase Plans SkyWest Retirement Plan The Company sponsors the SkyWest, Inc. Employees’ Retirement Plan (the “SkyWest Plan”). Employees who have completed 90 days of service and are at least 18 years of age are eligible for participation in the SkyWest Plan. Employees may elect to make contributions to the SkyWest Plan. Generally, the Company matches 100% of such contributions up to levels ranging from 2% to 12 % of compensation, based on position and years of service. Additionally, a discretionary contribution may be made by the Company. The Company’s combined contributions to the SkyWest Plan were $40.7 million, $35.6 million and $26.1 million for the years ended December 31, 2019, 2018 and 2017, respectively. Employee Stock Purchase Plans In May 2009, the Company’s Board of Directors approved the SkyWest, Inc. 2009 Employee Stock Purchase Plan (the “2009 Stock Purchase Plan”). All employees who have completed 90 days of employment with the Company or one of its subsidiaries are eligible to participate in the 2009 Stock Purchase Plan, except employees who own five percent or more of the Company’s common stock. The 2009 Stock Purchase Plan enables employees to purchase shares of the Company’s common stock at a five percent discount, through payroll deductions. Employees can contribute up to 15% of their base pay, not to exceed $25,000 each calendar year, for the purchase of shares. Shares are purchased semi-annually at a five percent discount based on the end of the period price. Employees can terminate their participation in the 2009 Stock Purchase Plan at any time upon written notice. The following table summarizes purchases made under the 2009 Employee Stock Purchase Plans during the years ended December 31, 2019, 2018 and 2017: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Number of shares purchased ​ 65,148 ​ 60,950 ​ 88,362 ​ Average price of shares purchased ​ $ 48.58 ​ $ 49.85 ​ $ 33.96 ​ The 2009 Stock Purchase Plan is a non-compensatory plan under the accounting guidance. Therefore, no compensation expense was recorded for the years ended December 31, 2019, 2018 and 2017.

Stock Repurchase

Stock Repurchase	12 Months Ended
	Dec. 31, 2019
Stock Repurchase
Stock Repurchase	(11) Stock Repurchase The Company’s Board of Directors has adopted a stock repurchase program which authorizes the Company to repurchase shares of the Company’s common stock in the public market or in private transactions, from time to time, at prevailing prices. The Company’s stock repurchase program authorizes the repurchase of up to $250.0 million of the Company’s common stock commencing on February 5, 2019, of which $159.6 million remained available at December 31, 2019. During the years ended December 31, 2019, 2018 and 2017, the Company repurchased 1.7 million, 1.0 million and 0.5 million shares of common stock (including shares purchased from the Company’s Chairman of the Board see Note 12 Related-Party Transactions for more details) for approximately $94.6 million, $54.4 million and $20.0 million, respectively at a weighted average price per share of $56.86, $56.25 and $41.36, respectively. Additionally, during the year ended December 31, 2019, 2018 and 2017, the Company paid

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions
Related Party Transactions	(12) Related-Party Transactions On June 13, 2019, the Company repurchased 268,025 shares of its common stock from Jerry Atkin, Chairman of the Board, at a price of $60.24 per share, representing the volume-weighted average price of the Company’s common stock over the five trading days immediately prior to such repurchase. The transaction was part of Mr. Atkin’s personal long-term strategy for asset diversification, tax and estate planning and to fund philanthropic and charitable efforts. The transaction was approved by the Company’s Audit Committee and was effected pursuant to the Company’s stock repurchase plan that commenced on February 5, 2019. ​ During the year ended December 31, 2019, the Company purchased $93,540 of spare aircraft parts from an entity affiliated with a director of the Company.

Gain on Sale of ExpressJet

Gain on Sale of ExpressJet	12 Months Ended
	Dec. 31, 2019
Gain on Sale of ExpressJet
Gain on Sale of ExpressJet	(13) Gain on Sale of ExpressJet On January 22, 2019, the Company completed the sale of its former wholly owned subsidiary ExpressJet. The Company recorded a gain of $46.5 million (pre-tax) from the sale of ExpressJet. The closing of the transaction was completed in two parts, through an asset sale and stock sale, as further described below. ​ Asset Sale ​ On January 11, 2019, pursuant to the terms and conditions of the Asset Purchase Agreement, dated as of December 17, 2018, by and among the Company, ExpressJet and United, United acquired certain specified assets and liabilities of ExpressJet, including, among other things, aircraft engines, auxiliary power units, rotable spare parts, ground support equipment and flight training equipment for $60.8 million in cash, subject to certain purchase price adjustments (the “Asset Sale”). Certain assets and liabilities of ExpressJet were expressly excluded from the Asset Sale. ​ Stock Sale ​ Additionally, on January 22, 2019, pursuant to the terms and conditions of the Stock Purchase Agreement, dated as of December 17, 2018, by and among the Company and ManaAir, LLC, a company in which United owns a minority interest (the “Buyer”), the Buyer acquired all of the outstanding shares of capital stock of ExpressJet from the Company for $18.8 million in cash, subject to certain purchase price adjustments (the “Stock Sale,”). To facilitate payment of the purchase price for the Stock Sale, at the closing of the Stock Sale, the Company loaned $26 million to Kair Enterprises, Inc. (the “Borrower”), the majority owner of the Buyer. Such loan accrues interest at the rate of 6.85% per annum, matures on the last business day of the last month immediately preceding the two-year anniversary of the closing of the Stock Sale and is secured by, among other things, the Borrower’s ownership interests in the Buyer. The Company also leased 16 CRJ200 aircraft to ExpressJet for a portion of the 2019 year. The lease of these 16 CRJ200 aircraft was terminated as of December 31, 2019.

Investment in Other Companies

Investment in Other Companies	12 Months Ended
	Dec. 31, 2019
Investment in Other Companies
Investment in Other Companies	(14) Investment in Other Companies During 2019, the Company created a joint venture with Regional One, Inc. (“Regional One”) by investing $22.3 million for a 75% ownership interest in Aero Engines, LLC. (“Aero Engines”). The primary purpose of Aero Engines is to lease engines to third parties. Aero Engines requires unanimous approval from the Company and Regional One for its engine purchases, dispositions, lease agreements with third parties and all other material transactions. The Company determined Aero Engines is a variable interest entity as the Company has a 75% ownership interest in Aero Engines and all material decisions require unanimous approval from the Company and Regional One, resulting in disproportionate ownership rights relative to voting rights. As unanimous approval is required for all Aero Engines’ material activities. Aero Engines has no primary beneficiary. The Company accounts for its investment in Aero Engines under the equity method. The Company’s exposure in its investment in Aero Engines primarily consists of the Company’s portion of income or loss from Aero Engines’ engine lease agreements with third parties and the Company’s ownership percentage in Aero Engines’ engines book value. The Company purchased

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Data (Unaudited)
Quarterly Financial Data (Unaudited)	(15) Quarterly Financial Data (Unaudited) Unaudited summarized financial data by quarter for 2019 and 2018 is as follows (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2019 ​ ​ First ​ Second ​ Third ​ Fourth ​ ​ ​ ​ ​ Quarter ​ Quarter ​ Quarter ​ Quarter ​ Year Operating revenues $ 723,694 $ 744,383 $ 760,295 $ 743,591 $ 2,971,963 ​ Operating income ​ 96,419 ​ 144,093 ​ 146,441 ​ 125,305 ​ 512,258 ​ Net income (1) ​ 88,181 ​ 88,052 ​ 91,339 ​ 72,527 ​ 340,099 ​ Net income per common share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ 1.71 ​ 1.72 ​ 1.80 ​ 1.44 ​ 6.68 ​ Diluted ​ 1.69 ​ 1.71 ​ 1.79 ​ 1.43 ​ 6.62 ​ Weighted average common shares: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic: ​ 51,440 ​ 51,145 ​ 50,746 ​ 50,395 ​ 50,932 ​ Diluted: ​ 52,098 ​ 51,477 ​ 51,129 ​ 50,796 ​ 51,375 ​ (1) Net income for the first quarter of 2019 included a $46.5 million gain related to the sale of ExpressJet (see Note 13 Gain on Sale of ExpressJet for more details) and a $21.9 million special charge (see Note 8 Special Items for more details). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2018 ​ ​ First ​ Second ​ Third ​ Fourth ​ ​ ​ ​ ​ Quarter ​ Quarter ​ Quarter ​ Quarter ​ Year Operating revenues $ 783,400 $ 805,515 $ 829,275 $ 803,489 $ 3,221,679 ​ Operating income ​ 88,175 ​ 126,678 ​ 137,925 ​ 121,502 ​ 474,280 ​ Net income ​ 54,362 ​ 75,859 ​ 83,046 ​ 67,105 ​ 280,372 ​ Net income per common share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ 1.05 ​ 1.46 ​ 1.60 ​ 1.30 ​ 5.40 ​ Diluted ​ 1.03 ​ 1.43 ​ 1.57 ​ 1.28 ​ 5.30 ​ Weighted average common shares: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic: ​ 51,921 ​ 52,046 ​ 52,039 ​ 51,650 ​ 51,914 ​ Diluted: ​ 53,033 ​ 52,913 ​ 52,981 ​ 52,556 ​ 52,871 ​ ​

SCHEDULE II-VALUATION AND QUALI

SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2019
SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS
SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS	SKYWEST, INC. AND SUBSIDIARIES SCHEDULE II—VALUATION AND QUALIFYING ACCOUNTS For the Years Ended December 31, 2019, 2018 and 2017 (Dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Additions ​ ​ ​ ​ ​ Balance at ​ Charged to ​ ​ ​ ​ ​ ​ ​ Beginning ​ Costs and ​ ​ ​ Balance at Description ​ of Year ​ Expenses ​ Deductions ​ End of Year Year ended December 31, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for inventory obsolescence ​ $ 22,141 ​ — (6,251) $ 15,890 ​ Allowance for doubtful accounts receivable ​ 158 ​ — (140) ​ 18 ​ ​ ​ $ 22,299 ​ — (6,391) $ 15,908 ​ Year ended December 31, 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for inventory obsolescence ​ $ 17,098 ​ 5,043 — $ 22,141 ​ Allowance for doubtful accounts receivable ​ 157 ​ 1 — ​ 158 ​ ​ ​ $ 17,255 ​ 5,044 — $ 22,299 ​ Year ended December 31, 2017: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for inventory obsolescence(1) ​ $ 40,497 ​ — (23,399) ​ $ 17,098 ​ Allowance for doubtful accounts receivable ​ 173 ​ — (16) ​ 157 ​ ​ ​ $ 40,670 ​ — (23,415) ​ $ 17,255 ​ ​ ​ ​ ​ ​ ​ (1) The deductions in 2017 related to the disposal of excess and obsolete inventory in 2017.

Nature of Operations and Summ_2

Nature of Operations and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Nature of Operations and Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The Company’s consolidated financial statements include the accounts of the Company and the SkyWest Airlines, ExpressJet (for the periods owned by the Company) and SkyWest Leasing segments, with all inter-company transactions and balances having been eliminated. In preparing the accompanying consolidated financial statements, the Company has reviewed, as determined necessary by the Company’s management, events that have occurred after December 31, 2019, through the filing date of the Company’s annual report with the U.S. Securities and Exchange Commission. The Company reclassified certain prior period amounts to conform to the current period presentation (see Recent Accounting Pronouncements).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less to be cash equivalents. The Company had no restricted cash as of December 31, 2019 and 2018.
Marketable securities	Marketable Securities The Company’s investments in debt securities are classified as available-for-sale and are reported at fair market value with the net unrealized appreciation reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. At the time of sale, any realized appreciation or depreciation, calculated by the specific identification method, is recognized in other income and expense. At December 31, 2019, the fair market value of the available-for-sale securities was the amortized cost. The Company’s position in marketable securities as of December 31, 2019 and 2018 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross unrealized ​ Gross unrealized ​ ​ ​ ​ At December 31, 2019 Amortized Cost holding gains holding losses Fair market value Total cash and cash equivalents ​ $ 87,206 ​ $ — ​ $ — ​ $ 87,206 ​ Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bond and bond funds ​ $ 267,243 ​ $ — ​ $ — ​ $ 267,243 ​ Commercial Paper ​ 165,723 ​ — ​ — ​ 165,723 ​ Total marketable securities ​ $ 432,966 ​ $ — ​ $ — ​ $ 432,966 ​ Total assets measured at fair value ​ $ 520,172 ​ $ — ​ $ — ​ $ 520,172 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross unrealized ​ Gross unrealized ​ ​ ​ ​ At December 31, 2018 Amortized Cost holding gains holding losses Fair market value Total cash and cash equivalents ​ $ 328,384 ​ $ — ​ $ — ​ $ 328,384 ​ Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bond and bond funds ​ $ 229,825 ​ $ — ​ $ (42) ​ $ 229,783 ​ Commercial Paper ​ 131,163 ​ — ​ (1) ​ 131,162 ​ Total marketable securities ​ $ 360,988 ​ $ — ​ $ (43) ​ $ 360,945 ​ Total assets measured at fair value ​ $ 689,372 ​ $ — ​ $ (43) ​ $ 689,329 ​ ​
Inventories	Inventories Inventories include expendable parts, fuel and supplies and are valued at cost (FIFO basis) less an allowance for obsolescence based on historical results, excess parts and management’s expectations of future operations. Expendable inventory parts are charged to expense as used. An obsolescence allowance for flight equipment expendable parts is accrued based on estimated lives of the corresponding fleet types and salvage values. The inventory allowance as of December 31, 2019 and 2018 was $15.9 million and $22.1 million, respectively.
Property and Equipment	Property and Equipment Property and equipment are stated at cost and depreciated over their useful lives to their estimated residual values using the straight-line method as follows: ​ ​ ​ Assets ​ Depreciable Life ​ Current Residual Value ​ Aircraft, rotable spares, and spare engines ​ up to 22 years up to 20 % ​ Ground equipment ​ up to 10 years 0 % ​ Office equipment ​ up to 7 years ​ 0 % ​ Leasehold improvements ​ Shorter of 15 years or lease term 0 % ​ Buildings ​ 20 - 39.5 years 0 % ​ ​
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets As of December 31, 2019, the Company had approximately $5.4 billion of property and equipment and related assets. In accounting for these long-lived and intangible assets, the Company makes estimates about the expected useful lives of the assets, the expected residual values of certain of these assets, and the potential for impairment based on the fair value of the assets and the cash flows they generate. Factors indicating potential impairment include, but are not limited to, significant decreases in the market value of the long-lived assets, a significant change in the condition of the long-lived assets and operating cash flow losses associated with the use of the long-lived assets. On a periodic basis, the Company evaluates whether impairment indicators are present. When considering whether or not impairment of long- lived assets exists, the Company groups similar assets together at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities and compare the undiscounted cash flows for each asset group to the net carrying amount of the assets supporting the asset group. Asset groupings are done at the fleet or contract level. The Company did not recognize any impairment charges of long-lived assets during the years ended December 31, 2019, 2018 and 2017.
Capitalized Interest	Capitalized Interest Interest is capitalized on aircraft purchase deposits as a portion of the cost of the asset and is depreciated over the estimated useful life of the asset. During the years ended December 31, 2019, 2018 and 2017, the Company capitalized interest costs of approximately $1.6 million, $1.5 million, and $1.4 million, respectively.
Maintenance	Maintenance The Company operates under a U.S. Federal Aviation Administration approved continuous inspection and maintenance program. The Company uses the direct expense method of accounting for its regional jet engine overhauls wherein the expense is recorded when the overhaul event occurs. The Company has engine services agreements with third-party vendors to provide long-term engine services covering the scheduled and unscheduled repairs for most of its aircraft. Under the terms of the agreements, the Company pays a fixed dollar amount per engine hour flown on a monthly basis and the third-party vendors will assume the responsibility to repair the engines at no additional cost to the Company, subject to certain specified exclusions. Maintenance costs under these contracts are recognized when the engine hour is flown pursuant to the terms of each contract. The costs of maintenance for airframe and avionics components, landing gear and other recurring maintenance are expensed as incurred.
Flying Agreements and Airport Customer Service and Other Revenues	Flying Agreements and Airport Customer Service and Other Revenues The Company recognizes flying agreements revenue and airport customer service and other revenues when the service is provided under its code-share agreements. Under the Company’s fixed-fee arrangements (referred to as “fixed-fee arrangements,” “fixed-fee contracts” or “capacity purchase agreements”) with Delta Air Lines, Inc. (“Delta”), United Airlines, Inc. (“United”), American Airlines, Inc. (“American”) and Alaska Airlines, Inc. (“Alaska”) (each, a “major airline partner”), the major airline partner generally pays the Company a fixed-fee for each departure, flight hour (measured from takeoff to landing, excluding taxi time) or block hour (measured from takeoff to landing, including taxi time) incurred, and an amount per aircraft in service each month with additional incentives based on flight completion and on-time performance. The major airline partner also directly pays for or reimburses the Company for certain direct expenses incurred under the fixed-fee arrangement, such as fuel, airport landing fees and airport rents. Under the fixed-fee arrangements, the Company’s performance obligation is met and revenue is recognized when each flight is completed and is reflected in flying agreements revenue. The transaction price for the fixed-fee agreements is determined from the fixed-fee consideration, incentive consideration and directly reimbursed expenses earned as flights are completed over the agreement term. For the year ended December 31, 2019, fixed-fee arrangements represented approximately Under the Company’s revenue-sharing arrangements (referred to as a “revenue-sharing” or “prorate” arrangement), the major airline partner and the Company negotiate a passenger fare proration formula, pursuant to which the Company receives a percentage of the ticket revenues for those passengers traveling for one portion of their trip on a Company airline and the other portion of their trip on the major airline partner. Under the Company’s prorate flying agreements, the performance obligation is met and revenue is recognized when each flight is completed based upon the portion of the prorate passenger fare the Company anticipates that it will receive for each completed flight. The transaction price for the prorate agreements is determined from the proration formula derived from each passenger ticket amount on each completed flight over the agreement term. For the year ended December 31, 2019, prorate flying arrangements represented approximately Airport customer service and other revenues primarily consist of ground handling functions, such as gate and ramp agent services at applicable airports where the Company provides such services. The transaction price for airport customer service agreements is determined from an agreed-upon rate by location applied to the applicable number of flights handled by the Company over the agreement term. Additionally, airport customer service and other revenues includes revenue generated from aircraft and spare engines leased to third parties. Of the Company’s $5.4 billion of property and equipment, net as of December 31, 2019, $97.0 million of regional jet aircraft and spare engines was leased to third parties under operating leases. The Company mitigates the residual asset risks of these assets by leasing aircraft and engine types that can be operated by the Company in the event of a default. A portion of the Company’s leases to third parties contain variable payments from lessees based on departures where the Company pays for maintenance. Additionally, the operating leases typically have specified lease return condition requirements paid by the lessee to the Company and the Company typically maintains inspection rights under the leases. ​ The following table represents the Company’s airport customer service and other revenue for the years ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2019 2018 2017 Airport customer service revenue ​ $ 45,538 ​ $ 48,236 ​ $ 41,002 Operating lease income relating to lease payments ​ 27,552 ​ 3,923 ​ 3,293 Operating lease income relating to variable lease payments ​ 9,608 ​ — ​ — Airport customer service and other ​ $ 82,698 ​ $ 52,159 ​ $ 44,295 ​ ​ ​ The following table summarizes future minimum rental income under operating leases primarily related to leased aircraft that had remaining non-cancelable lease terms as of December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 $ 32,724 2021 ​ 31,344 ​ 2022 ​ 24,786 ​ 2023 ​ 18,530 ​ 2024 ​ 18,222 ​ Thereafter ​ 54,932 ​ ​ ​ $ 180,538 ​ ​ Other ancillary revenues commonly associated with airlines, such as baggage fee revenue, ticket change fee revenue and the marketing component of the sale of mileage credits, are retained by the Company’s major airline partners on flights that the Company operates under its code-share agreements. ​ The following table represents the Company’s flying agreements revenue by type for the years ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2019 2018 2017 Capacity purchase agreements revenue: flight operations ​ $ 1,538,062 ​ $ 1,856,253 ​ $ 1,805,510 Capacity purchase agreements revenue: aircraft lease ​ 830,247 ​ 814,518 ​ 834,366 Prorate agreements revenue ​ 520,956 ​ 498,749 ​ 438,421 Flying agreements revenue ​ $ 2,889,265 ​ $ 3,169,520 ​ $ 3,078,297 ​ A portion of the Company’s compensation under its fixed-fee agreements is designed to reimburse the Company for certain aircraft ownership costs. The consideration for aircraft ownership costs varies by agreement but is intended to cover either the Company’s aircraft principal and interest debt service costs, its aircraft depreciation and interest expense or its aircraft lease expense costs while the aircraft is under contract. The consideration received for the use of the aircraft under the Company’s fixed-fee agreements is reflected as lease revenue, inasmuch as the agreements identify the “right of use” of a specific type and number of aircraft over a stated period of time. The lease revenue associated with the Company’s fixed-fee agreements is accounted for as an operating lease and is reflected as flying agreements revenue on the Company’s consolidated statements of comprehensive income. The Company has not separately stated aircraft rental income and aircraft rental expense in the consolidated statement of comprehensive income since the use of the aircraft is not a separate activity of the total service provided. The Company’s fixed-fee and prorate agreements include weekly provisional cash payments from the respective major airline partner based on a projected level of flying each month. The Company and each major airline partner subsequently reconcile these payments to the actual completed flight activity on a monthly or quarterly basis. ​ In the event a flying agreement includes a mid-term rate reset to adjust rates prospectively and the contractual rates under the Company’s flying agreements have not been finalized at quarterly or annual financial statement dates, the Company applies the variable constraint guidance under Topic 606, where the Company records revenue to the extent it believes that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. ​ In several of the Company’s agreements, the Company is eligible to receive incentive compensation upon the achievement of certain performance criteria. The incentives are defined in the agreements and are measured and determined on a monthly, quarterly or semi-annual basis. At the end of each period during the term of an agreement, the Company calculates the incentives achieved during that period and recognizes revenue attributable to that agreement accordingly, subject to the variable constraint guidance under Topic 606. The following summarizes the significant provisions of each code-share agreement the Company has with each major airline partner through SkyWest Airlines: Delta Connection Agreements Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates Delta Connection Agreement (fixed-fee arrangement) ​ ● CRJ 200 ● CRJ 700 ● CRJ 900 ● E175 ​ 55 13 43 59 ​ ● Individual aircraft have scheduled removal dates from 2020 to 2029 ● ​ Delta Connection Prorate Agreement (revenue-sharing arrangement) ​ ● CRJ 200 ​ 29 ​ ● Terminable with 30-day ​ ​ United Express Agreements ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates United Express Agreements (fixed-fee arrangement) ​ ● CRJ 200 ● CRJ 700 ● E175 ​ 68 19 65 ​ ​ ● Individual aircraft have scheduled removal dates under the agreement between 2020 and 2029 ● ​ United Express Prorate Agreement (revenue-sharing arrangement) ​ ● CRJ 200 ​ ​ 31 ​ ● Terminable with 120-day ​ ​ American Agreements ​ ​ ​ ​ ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates American Agreement (fixed-fee arrangement) ​ ● CRJ 700 ​ ​ 62 ​ ● ● ​ American Prorate Agreement (revenue-sharing arrangement) ​ ● ​ 7 ​ ● 120-day ​ ​ Alaska Capacity Purchase Agreement ​ ​ ​ ​ ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates Alaska Agreement (fixed-fee arrangement) ​ ● E175 ​ ​ 32 ​ ● ● ​ ​ In addition to the contractual arrangements described above, SkyWest Airlines has entered into fixed-fee agreements with Delta and American to place additional E175 aircraft into service. As of December 31, 2019, the Company was scheduled to take delivery of new E175 aircraft in connection with its agreement with American. The delivery dates for the new E175 aircraft are currently scheduled to be completed by the end of 2021. Final delivery dates may be adjusted based on various factors. Additionally, the Company is scheduled to add an additional six used E175 aircraft under the Delta agreement during 2020. ​ SkyWest Airlines also entered into an agreement with Delta to place one CRJ900 aircraft under a nine-year fixed-fee agreement in 2020. ​ SkyWest Airlines also entered into an agreement with American to place ten used CRJ700s under a multi-year contract. As of December 31, 2019, SkyWest Airlines had placed two of these CRJ700 aircraft into service with American. When an aircraft is scheduled to be removed from a fixed-fee arrangement, the Company may, as practical under the circumstances, negotiate an extension with the respective major airline partner, negotiate the placement of the aircraft with another major airline partner, return the aircraft to the lessor if the aircraft is leased and the lease is expiring, place owned aircraft for sale, or pursue other uses for the aircraft. Other uses for the aircraft may include placing the aircraft in a prorate arrangement, leasing the aircraft to a third party or parting out the aircraft to use the engines and parts as spare inventory or to lease the engines to a third party. ​ Airport customer service and other revenues primarily consist of ground handling functions, such as gate and ramp agent services at applicable airports where the Company provides such services. The transaction price for airport service agreements is determined from an agreed-upon rate by location applied to the applicable number of flights handled (measured by departures) by the Company over the agreement term. ​ The Company’s operating revenues could be impacted by a number of factors, including changes to the Company’s code-share agreements with its major airline partners, changes in flight schedules, contract modifications resulting from contract renegotiations, the Company’s ability to earn incentive payments contemplated under the Company’s code-share agreements and settlement of reimbursement disputes with the Company’s major airline partners. ​ As of December 31, 2019, the Company had $83.0 million in accounts receivable of which $58.8 million related to flying agreements. As of December 31, 2018, the Company had $64.2 million in accounts receivable of which $52.7 million related to flying agreements.
Income Taxes	Income Taxes The Company recognizes a net liability or asset for the deferred tax consequences of all temporary differences between the tax basis of assets and liabilities and their reported amounts in the consolidated financial statements that are expected to result in taxable or deductible amounts in future years when the reported amounts of the assets and liabilities are recovered or settled.
Net Income Per Common Share	Net Income Per Common Share Basic net income per common share (“Basic EPS”) excludes dilution and is computed by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per common share (“Diluted EPS”) reflects the potential dilution that could occur if stock options or other contracts to issue common stock were exercised or converted into common stock. The computation of Diluted EPS does not assume exercise or conversion of securities that would have an anti-dilutive effect on net income (loss) per common share. During the year ended December 31, 2019, 150,000 performance share units (at target performance) were excluded in the computation of Diluted EPS since the Company had not achieved the minimum target thresholds as of December 31, 2019. During the year ended December 31, 2018, 207,000 performance share units (at target performance) were excluded in the computation of Diluted EPS since the Company had not achieved the minimum target thresholds as of December 31, 2018. During the year ended December 31, 2017, 284,000 performance share units (at target performance) were excluded in the computation of Diluted EPS since the Company had not achieved the minimum target thresholds as of December 31, 2017. The calculation of the weighted average number of common shares outstanding for Basic EPS and Diluted EPS are as follows for the years ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Numerator: ​ ​ ​ ​ Net Income ​ $ 340,099 ​ $ 280,372 ​ $ 428,907 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share weighted average shares ​ 50,932 ​ 51,914 ​ 51,804 ​ Dilution due to stock options and restricted stock units ​ 443 ​ 957 ​ 1,296 ​ Diluted earnings per share weighted average shares ​ 51,375 ​ 52,871 ​ 53,100 ​ Basic earnings per share ​ $ 6.68 ​ $ 5.40 ​ $ 8.28 ​ Diluted earnings per share ​ $ 6.62 ​ $ 5.30 ​ $ 8.08 ​ ​
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) includes charges and credits to stockholders’ equity that are not the result of transactions with the Company’s shareholders, including changes in unrealized appreciation on marketable debt securities.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts reported in the consolidated balance sheets for receivables and accounts payable approximate fair values because of the immediate or short-term maturity of these financial instruments. Marketable securities are reported at fair value based on market quoted prices in the consolidated balance sheets. If quoted prices in active markets are no longer available, the Company has estimated the fair values of these securities utilizing a discounted cash flow analysis. These analyses consider, among other items, the collateralization underlying the security investments, the creditworthiness of the counterparty, the timing of expected future cash flows, and the expectation of the next time the security is expected to have a successful auction. The fair value of the Company’s long-term debt is estimated based on current rates offered to the Company for similar debt and was approximately $3,049.1 million as of December 31, 2019, as compared to the carrying amount of $3,017.5 million as of December 31, 2019. The Company’s fair value of long-term debt as of December 31, 2018 was $3,157.3 million as compared to the carrying amount of $3,185.4 million as of December 31, 2018.
Segment Reporting	Segment Reporting Generally accepted accounting principles require disclosures related to components of a company for which separate financial information is available to, and regularly evaluated by, the Company’s chief operating decision maker when deciding how to allocate resources and in assessing performance. The Company’s three operating segments (prior to the sale of ExpressJet in January 2019) consist of the operations conducted by SkyWest Airlines, ExpressJet (for the periods owned by the Company) and SkyWest Leasing. Following the sale of ExpressJet, the Company has two reportable segments: SkyWest Airlines and SkyWest Leasing. Information pertaining to the Company’s reportable segments is presented in Note 2, Segment Reporting
Recent Accounting Pronouncements	Recent Accounting Pronouncements ​ Standards Effective in Future Years and Not Yet Adopted In June 2016, the Financial Accounting Standards Board (the “FASB”) issued ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments” (“Topic 326”), which requires measurement and recognition of expected credit losses for financial assets held and requires enhanced disclosure regarding significant estimates and judgments used in estimating credit losses. Topic 326 is effective for the Company beginning January 1, 2020. The Company will adopt Topic 326, on January 1, 2020. The Company’s primary financial assets as of December 31, 2019, include trade receivables from its flying agreements, notes and other receivables from third parties. The Company estimates it will record a credit loss amount between Recently Adopted Standards In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (“Topic 842”). Topic 842 and subsequently issued amendments require certain leases with durations longer than 12 months to be recognized on the balance sheet. The Company adopted Topic 842 effective January 1, 2019 and elected the package of transition practical expedients for expired or existing contracts, which does not require reassessment of: (1) whether any of the Company’s contracts are or contain leases, (2) lease classification and (3) initial direct costs. In July 2018, the FASB issued ASU No. 2018-11, “Targeted Improvements - Leases (Topic 842).” This update provides an optional transition method that allows entities to elect to apply the standard using the modified retrospective approach at its effective date, versus recasting the prior years presented. If this adoption method is elected, an entity would recognize a cumulative-effect adjustment to the opening balance of retained earnings in the year of adoption. The Company elected this adoption method and recognized a cumulative-effect adjustment to the opening balance of retained earnings on January 1, 2019. ​ Additionally, the Company’s adoption of Topic 842 did not have a significant impact on the recognition, measurement or presentation of lease revenue and lease expenses within the condensed consolidated statements of operations and comprehensive income or the condensed consolidated statements of cash flows. The Company’s adoption of Topic 842 did not have a material impact on the timing or amount of the Company’s lease revenue as a lessor. The Company’s prepaid aircraft rents, accrued aircraft rents and deferred rent credits that were separately stated in the Company’s December 31, 2018 balance sheet have been classified as a component of the Company’s right-of-use assets effective January 1, 2019. The consolidated financial statements for 2019 are presented under the new standard, while comparative years presented are not adjusted and continue to be reported in accordance with the Company’s historical accounting policy. ​ See Note 6, " Leases

Nature of Operations and Summ_3

Nature of Operations and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Schedule of number of aircraft held by entity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CRJ200 CRJ700 CRJ900 E175 Total Delta 84 ​ 13 ​ 43 ​ 59 ​ 199 ​ United 99 ​ 19 ​ — ​ 65 ​ 183 ​ American 7 ​ 62 ​ — ​ — ​ 69 ​ Alaska — ​ — ​ — ​ 32 ​ 32 ​ Aircraft in scheduled service ​ 190 ​ 94 ​ 43 ​ 156 ​ 483 ​ Subleased to an un-affiliated entity 4 ​ 10 ​ 5 ​ — ​ 19 ​ Other* 20 ​ 22 ​ — ​ — ​ 42 ​ Total Fleet 214 ​ 126 ​ 48 ​ 156 ​ 544 ​ *As of December 31, 2019, these aircraft have been removed from service and are in the process of being placed under a leasing arrangement with a third party, are aircraft transitioning between code-share agreements with the Company’s major airline partners and being used as a supplemental spare aircraft, or are in the process of being parted out.
Schedule of marketable securities	At December 31, 2019, the fair market value of the available-for-sale securities was the amortized cost. The Company’s position in marketable securities as of December 31, 2019 and 2018 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross unrealized ​ Gross unrealized ​ ​ ​ ​ At December 31, 2019 Amortized Cost holding gains holding losses Fair market value Total cash and cash equivalents ​ $ 87,206 ​ $ — ​ $ — ​ $ 87,206 ​ Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bond and bond funds ​ $ 267,243 ​ $ — ​ $ — ​ $ 267,243 ​ Commercial Paper ​ 165,723 ​ — ​ — ​ 165,723 ​ Total marketable securities ​ $ 432,966 ​ $ — ​ $ — ​ $ 432,966 ​ Total assets measured at fair value ​ $ 520,172 ​ $ — ​ $ — ​ $ 520,172 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross unrealized ​ Gross unrealized ​ ​ ​ ​ At December 31, 2018 Amortized Cost holding gains holding losses Fair market value Total cash and cash equivalents ​ $ 328,384 ​ $ — ​ $ — ​ $ 328,384 ​ Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bond and bond funds ​ $ 229,825 ​ $ — ​ $ (42) ​ $ 229,783 ​ Commercial Paper ​ 131,163 ​ — ​ (1) ​ 131,162 ​ Total marketable securities ​ $ 360,988 ​ $ — ​ $ (43) ​ $ 360,945 ​ Total assets measured at fair value ​ $ 689,372 ​ $ — ​ $ (43) ​ $ 689,329 ​
Schedule of property and equipment	​ ​ ​ Assets ​ Depreciable Life ​ Current Residual Value ​ Aircraft, rotable spares, and spare engines ​ up to 22 years up to 20 % ​ Ground equipment ​ up to 10 years 0 % ​ Office equipment ​ up to 7 years ​ 0 % ​ Leasehold improvements ​ Shorter of 15 years or lease term 0 % ​ Buildings ​ 20 - 39.5 years 0 % ​
Schedule of future minimum rental payments for operating leases	​ ​ ​ ​ ​ ​ 2020 $ 94,806 2021 ​ 84,285 ​ 2022 ​ 73,960 ​ 2023 ​ 68,581 ​ 2024 ​ 27,282 ​ Thereafter ​ 94,746 ​ ​ ​ $ 443,660 ​
Schedule of net income (loss) per common share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Numerator: ​ ​ ​ ​ Net Income ​ $ 340,099 ​ $ 280,372 ​ $ 428,907 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share weighted average shares ​ 50,932 ​ 51,914 ​ 51,804 ​ Dilution due to stock options and restricted stock units ​ 443 ​ 957 ​ 1,296 ​ Diluted earnings per share weighted average shares ​ 51,375 ​ 52,871 ​ 53,100 ​ Basic earnings per share ​ $ 6.68 ​ $ 5.40 ​ $ 8.28 ​ Diluted earnings per share ​ $ 6.62 ​ $ 5.30 ​ $ 8.08 ​
Flying agreements
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Schedule of revenue	The following table represents the Company’s flying agreements revenue by type for the years ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2019 2018 2017 Capacity purchase agreements revenue: flight operations ​ $ 1,538,062 ​ $ 1,856,253 ​ $ 1,805,510 Capacity purchase agreements revenue: aircraft lease ​ 830,247 ​ 814,518 ​ 834,366 Prorate agreements revenue ​ 520,956 ​ 498,749 ​ 438,421 Flying agreements revenue ​ $ 2,889,265 ​ $ 3,169,520 ​ $ 3,078,297
Airport customer service and other
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Schedule of revenue	The following table represents the Company’s airport customer service and other revenue for the years ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2019 2018 2017 Airport customer service revenue ​ $ 45,538 ​ $ 48,236 ​ $ 41,002 Operating lease income relating to lease payments ​ 27,552 ​ 3,923 ​ 3,293 Operating lease income relating to variable lease payments ​ 9,608 ​ — ​ — Airport customer service and other ​ $ 82,698 ​ $ 52,159 ​ $ 44,295
Delta Connection Agreement
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Schedule of details of aircraft and agreements with other airlines	Delta Connection Agreements Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates Delta Connection Agreement (fixed-fee arrangement) ​ ● CRJ 200 ● CRJ 700 ● CRJ 900 ● E175 ​ 55 13 43 59 ​ ● Individual aircraft have scheduled removal dates from 2020 to 2029 ● ​ Delta Connection Prorate Agreement (revenue-sharing arrangement) ​ ● CRJ 200 ​ 29 ​ ● Terminable with 30-day ​
United Express Agreements
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Schedule of details of aircraft and agreements with other airlines	United Express Agreements ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates United Express Agreements (fixed-fee arrangement) ​ ● CRJ 200 ● CRJ 700 ● E175 ​ 68 19 65 ​ ​ ● Individual aircraft have scheduled removal dates under the agreement between 2020 and 2029 ● ​ United Express Prorate Agreement (revenue-sharing arrangement) ​ ● CRJ 200 ​ ​ 31 ​ ● Terminable with 120-day ​
American Agreements
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Schedule of details of aircraft and agreements with other airlines	American Agreements ​ ​ ​ ​ ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates American Agreement (fixed-fee arrangement) ​ ● CRJ 700 ​ ​ 62 ​ ● ● ​ American Prorate Agreement (revenue-sharing arrangement) ​ ● ​ 7 ​ ● 120-day ​
Alaska Capacity Purchase Agreement
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Schedule of details of aircraft and agreements with other airlines	Alaska Capacity Purchase Agreement ​ ​ ​ ​ ​ Agreement Aircraft type ​ Number of Aircraft Term / Termination Dates Alaska Agreement (fixed-fee arrangement) ​ ● E175 ​ ​ 32 ​ ● ● ​
Aircraft
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Schedule of future minimum rental payments for operating leases	The following table summarizes future minimum rental income under operating leases primarily related to leased aircraft that had remaining non-cancelable lease terms as of December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 $ 32,724 2021 ​ 31,344 ​ 2022 ​ 24,786 ​ 2023 ​ 18,530 ​ 2024 ​ 18,222 ​ Thereafter ​ 54,932 ​ ​ ​ $ 180,538 ​

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting
Schedule of Company's segment data	The following represents the Company’s segment data for the years ended December 31, 2019, 2018 and 2017 (in thousands). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 ​ ​ ​ SkyWest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Airlines ​ ​ ExpressJet ​ ​ SkyWest Leasing ​ ​ Consolidated Operating revenues ​ $ 2,478,681 ​ $ 24,050 ​ $ 469,232 ​ $ 2,971,963 ​ Operating expense ​ 2,214,632 ​ ​ 28,690 ​ ​ 216,383 ​ 2,459,705 ​ Depreciation and amortization expense ​ 168,246 ​ 971 ​ 198,881 ​ 368,098 ​ Special items ​ ​ 18,508 ​ ​ 3,361 ​ ​ — ​ ​ 21,869 ​ Interest expense ​ 13,525 ​ — ​ 114,230 ​ 127,755 ​ Segment profit (loss) (1) ​ 250,524 ​ (4,640) ​ 138,619 ​ 384,503 ​ Total assets ​ 2,728,964 ​ — ​ 3,928,165 ​ 6,657,129 ​ Capital expenditures (including non-cash) ​ 270,191 ​ — ​ 576,279 ​ 846,470 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2018 ​ ​ ​ SkyWest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Airlines ​ ​ ExpressJet ​ ​ SkyWest Leasing ​ ​ Consolidated Operating revenues ​ $ 2,346,251 ​ $ 564,202 ​ $ 311,226 ​ $ 3,221,679 ​ Operating expense ​ 2,022,560 ​ ​ 577,608 ​ ​ 147,231 ​ 2,747,399 ​ Depreciation and amortization expense ​ 155,511 ​ 37,290 ​ 141,788 ​ 334,589 ​ Interest expense ​ 17,021 ​ 2,340 ​ 101,048 ​ 120,409 ​ Segment profit (loss) (1) ​ 306,670 ​ (15,746) ​ 62,947 ​ 353,871 ​ Total assets ​ 2,531,707 ​ 279,303 ​ 3,502,202 ​ 6,313,212 ​ Capital expenditures (including non-cash) ​ 149,731 ​ 10,137 ​ 996,408 ​ 1,156,276 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2017 ​ ​ ​ ​ SkyWest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Airlines ​ ​ ExpressJet ​ ​ SkyWest Leasing ​ ​ Consolidated Operating revenues ​ $ 2,092,368 ​ $ 790,282 ​ $ 239,942 ​ $ 3,122,592 ​ Operating expense ​ 1,807,540 ​ ​ 818,683 ​ ​ 108,170 ​ ​ 2,734,393 ​ Depreciation and amortization expense ​ 134,563 ​ 51,982 ​ 106,223 ​ ​ 292,768 ​ Interest expense ​ 21,544 ​ 4,127 ​ 79,254 ​ ​ 104,925 ​ Segment profit (loss) (1) ​ 263,284 ​ (32,528) ​ 52,518 ​ 283,274 ​ Identifiable intangible assets, other than goodwill ​ — ​ ​ 4,896 ​ ​ — ​ ​ 4,896 ​ Total assets ​ 2,245,051 ​ ​ 599,122 ​ ​ 2,630,227 ​ ​ 5,474,400 ​ Capital expenditures (including non-cash) ​ 124,955 ​ 14,278 ​ 550,165 ​ 689,398 ​ (1) Segment profit is operating income less interest expense

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Long-Term Debt
Schedule of long-term debt	Long-term debt consisted of the following as of December 31, 2019 and 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2019 ​ 2018 Notes payable to banks, due in semi-annual installments, variable interest based on LIBOR, or with an interest rate of 4.00% through 2019, secured by aircraft ​ $ — ​ $ 6,429 ​ Notes payable to a financing company, due in semi-annual installments, with a fixed interest rate of 3.25% through 2021, secured by aircraft ​ 18,412 ​ 36,324 ​ Notes payable to banks, due in semi-annual installments plus interest at 6.10% to 6.51% through 2021, secured by aircraft ​ 22,557 ​ 41,592 ​ Notes payable to banks, due in monthly installments, plus interest at 1.95% to 6.86% through 2029, secured by aircraft ​ 438,878 ​ 476,369 ​ Notes payable to banks, due in quarterly installments, plus interest at 3.39% to 5.08% through 2031, secured by aircraft ​ ​ 2,537,676 ​ ​ 2,621,416 ​ Notes payable to banks due in monthly installments, interest at 3.30% through 2019, secured by spare engines ​ — ​ 3,308 ​ Long-term debt ​ $ 3,017,523 ​ $ 3,185,438 ​ Current portion of long-term debt ​ (367,954) ​ (354,072) ​ Less long-term portion of unamortized debt issue cost, net ​ ​ (20,580) ​ ​ (21,598) ​ Long-term debt, net of current maturities and debt issue costs ​ $ 2,628,989 ​ $ 2,809,768 ​ ​ ​ ​ ​ ​ ​ ​ ​ Current portion of long-term debt ​ 367,954 ​ 354,072 ​ Less current portion of unamortized debt issue cost, net ​ ​ (3,828) ​ ​ (3,866) ​ Current portion of long-term debt, net of debt issue costs ​ $ 364,126 ​ $ 350,206 ​
Schedule of maturities of long-term debt	The aggregate amounts of principal maturities of long-term debt as of December 31, 2019 were as follows (in thousands): ​ ​ ​ ​ ​ 2020 $ 367,954 2021 ​ 352,005 ​ 2022 ​ 365,907 ​ 2023 ​ 374,906 ​ 2024 ​ 327,630 ​ Thereafter ​ 1,229,121 ​ ​ ​ $ 3,017,523 ​

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Taxes
Schedule of components of provision (benefit) for income taxes	The provision (benefit) for income taxes includes the following components (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Current tax provision (benefit): ​ ​ ​ ​ Federal ​ $ (4,395) ​ $ (21,598) ​ $ 5,853 ​ State ​ 891 ​ 1,465 ​ 180 ​ Foreign ​ ​ — ​ ​ 1,575 ​ ​ — ​ ​ ​ (3,504) ​ (18,558) ​ 6,033 ​ Deferred tax provision (benefit): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ 95,655 ​ 92,250 ​ (166,890) ​ State ​ 14,055 ​ 12,250 ​ 20,133 ​ ​ ​ 109,710 ​ 104,500 ​ (146,757) ​ Provision (benefit) for income taxes ​ $ 106,206 ​ $ 85,942 ​ $ (140,724) ​
Schedule of income tax rate reconciliation	The following is a reconciliation between a federal income tax rate of 21% in 2019 and 2018 and 35% for 2017 of income before income taxes and the effective tax rate which is derived by dividing the provision (benefit) for income taxes by the income before the provision for income taxes (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Computed provision for income taxes at the statutory rate $ 93,724 $ 76,926 $ 100,864 ​ Increase (decrease) in income taxes resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ State income tax provision, net of federal income tax benefit ​ 15,645 ​ 12,711 ​ 7,778 ​ Non-deductible expenses ​ ​ 3,934 ​ ​ 1,956 ​ ​ 3,230 ​ Valuation allowance changes affecting the provision for income taxes ​ (517) ​ (1,187) ​ 505 ​ Foreign income taxes, net of federal & state benefit ​ ​ — ​ ​ 1,192 ​ ​ — ​ Excess tax benefits from share-based compensation ​ ​ (3,525) ​ ​ (4,548) ​ ​ (5,377) ​ Revaluation of net deferred taxes for the Tax Cuts and Jobs Act of 2017 ​ ​ — ​ ​ — ​ ​ (246,845) ​ Other, net ​ (3,055) ​ (1,108) ​ (879) ​ Provision (benefit) for income taxes ​ $ 106,206 ​ $ 85,942 ​ $ (140,724) ​
Schedule of components of the net deferred tax assets and liabilities	The significant components of the Company’s net deferred tax assets and liabilities as of December 31, 2019 and 2018 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2019 ​ 2018 Deferred tax assets: ​ ​ ​ Accrued benefits ​ $ 20,848 ​ $ 32,462 ​ Net operating loss carryforward ​ 358,685 ​ 344,375 ​ AMT credit carryforward ​ 4,397 ​ 15,744 ​ Aircraft credits ​ 9,114 ​ 35,924 ​ Accrued reserves and other ​ 17,225 ​ 18,710 ​ Total deferred tax assets ​ 410,269 ​ 447,215 ​ Valuation allowance ​ (892) ​ (9,455) ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ Accelerated depreciation ​ (1,032,957) ​ (955,919) ​ Total deferred tax liabilities ​ (1,032,957) ​ (955,919) ​ Net deferred tax liability ​ $ (623,580) ​ $ (518,159) ​
Schedule of unrecognized tax benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits for the year ended December 31, 2019 and 2018 is as follows (in thousands) : ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2019 2018 Unrecognized tax benefits at the beginning of year ​ $ 14,553 ​ $ 2,223 Gross increases - current year tax positions ​ ​ — ​ 13,899 ​ Gross increases - prior year tax positions ​ ​ 67 ​ — ​ Gross decreases - prior year tax positions ​ — ​ (1,569) ​ Unrecognized tax benefits at end of year ​ $ 14,620 ​ $ 14,553 ​ Interest and penalties in year-end balance ​ $ 67 ​ $ — ​

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases
Summary of related terms and discount rates	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2019 Weighted-average remaining lease term ​ Operating leases ​ ​ 6.84 years ​ Weighted-average discount rate ​ ​ ​ Operating leases ​ ​ 6.4% ​
Summary of lease costs	The Company’s lease costs for 2019 and 2018 included the following components (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2019 2018 Operating lease cost $ 104,011 $ 185,337 Variable and short-term lease cost ​ 5,232 ​ 5,143 Sublease income ​ ​ (1,436) ​ ​ — Total lease cost $ 107,807 $ 190,480
Schedule of future minimum rental payments for operating leases	​ ​ ​ ​ ​ ​ 2020 $ 94,806 2021 ​ 84,285 ​ 2022 ​ 73,960 ​ 2023 ​ 68,581 ​ 2024 ​ 27,282 ​ Thereafter ​ 94,746 ​ ​ ​ $ 443,660 ​
Schedule of Future Minimum Rental Payments for Operating Leases	​ ​ ​ ​ ​ ​ 2019 $ 87,256 2020 ​ 101,741 ​ 2021 ​ 90,787 ​ 2022 ​ 72,593 ​ 2023 ​ 65,749 ​ Thereafter ​ 59,820 ​ ​ ​ $ 477,946 ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Measurements
Schedule of assets measured at fair value on a recurring basis	As of December 31, 2019, the Company held certain assets that are required to be measured at fair value on a recurring basis. Assets measured at fair value on a recurring basis are summarized below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements as of December 31, 2019 ​ ​ Total Level 1 Level 2 Level 3 Marketable Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bonds and bond funds ​ $ 267,243 ​ $ — ​ $ 267,243 ​ $ — ​ Commercial paper ​ 165,723 ​ — ​ 165,723 ​ — ​ ​ ​ $ 432,966 ​ $ — ​ $ 432,966 ​ $ — ​ Cash, Cash Equivalents and Restricted Cash ​ ​ 87,206 ​ 87,206 ​ — ​ — ​ Total Assets Measured at Fair Value ​ $ 520,172 ​ $ 87,206 ​ $ 432,966 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements as of December 31, 2018 ​ ​ Total ​ Level 1 ​ Level 2 ​ Level 3 Marketable Securities ​ ​ ​ ​ ​ Bonds and bond funds ​ $ 229,783 ​ $ — ​ $ 229,783 ​ $ — ​ Commercial paper ​ 131,162 ​ — ​ 131,162 ​ — ​ ​ ​ $ 360,945 ​ $ — ​ $ 360,945 ​ $ — ​ Cash, Cash Equivalents and Restricted Cash ​ ​ 328,384 ​ 328,384 ​ — ​ — ​ Total Assets Measured at Fair Value ​ $ 689,329 ​ $ 328,384 ​ $ 360,945 ​ $ — ​

Special Items (Tables)

Special Items (Tables)	12 Months Ended
	Dec. 31, 2019
Special Items
Summary of the components of special items	The following table summarizes the components of the Company's special items, for the year ended December 31, 2019, 2018 and 2017 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2019 2018 2017 Special items: ​ ​ ​ ​ ​ ​ ​ ​ ​ Parts credit 1 ​ $ 18,508 ​ $ — ​ $ — Employee severance 2 ​ 3,361 ​ ​ — ​ — Total special items ​ $ 21,869 ​ $ — ​ $ — (1) The Company terminated an agreement with an aircraft manufacturer that obligated the Company to future aircraft lease return conditions on aircraft the Company leased. In conjunction with the terminated agreement, the aircraft manufacturer released the Company from the future aircraft lease return obligations and the Company agreed to terminate aircraft part credits previously issued by the manufacturer to the Company. As a result of the terminated agreement, the Company recorded a non-cash expense of $18.5 million (pre-tax) during 2019 to write-off the terminated aircraft part credits, which was reflected as a special items operating expense in the consolidated statement of comprehensive income. These special items are reflected in the SkyWest Airlines operating expenses under Note 2 Segment Reporting . ​ (2) During 2019, the Company incurred $3.4 million of employee severance related costs associated with the sale of ExpressJet that are also reflected in special items. These special items are reflected in the ExpressJet operating expenses under Note 2 Segment Reporting .

Capital Transactions (Tables)

Capital Transactions (Tables)	12 Months Ended
	Dec. 31, 2019
Schedule of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ 2018 ​ 2017 ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ Aggregate ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ Remaining ​ Intrinsic ​ ​ ​ Average ​ ​ ​ Average ​ ​ Number of ​ Exercise ​ Contractual ​ Value ​ Number of ​ Exercise ​ Number of ​ Exercise ​ ​ Options ​ Price ​ Term ​ ($000) ​ Options ​ Price ​ Options ​ Price Outstanding at beginning of year 300,580 ​ $ 13.70 3.0 years $ 9,249.4 458,103 $ 13.73 819,981 $ 13.58 ​ Granted — ​ — ​ ​ ​ ​ ​ — ​ — — ​ — ​ Exercised (232,514) ​ 13.36 ​ ​ ​ ​ ​ (157,523) ​ 13.80 (356,209) ​ 13.36 ​ Cancelled (7,835) ​ 15.86 ​ ​ ​ ​ ​ — ​ — (5,669) ​ 14.33 ​ Outstanding at end of year 60,231 ​ 14.74 3.1 years $ 3,005.1 300,580 ​ 13.70 458,103 ​ 13.73 ​ Exercisable at December 31, 2019 60,231 ​ ​ 14.74 ​ 3.1 years $ 3,005.1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exercisable at December 31, 2018 235,672 ​ ​ 13.36 ​ 2.7 years $ 7,330.7 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of non-vested stock options	The following table summarizes the status of the Company’s non-vested stock options as of December 31, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ Number of ​ Grant-Date ​ ​ Shares ​ Fair Value Non-vested shares at beginning of year 64,908 ​ $ 5.32 ​ Granted — ​ ​ — ​ Vested (57,073) ​ 5.27 ​ Cancelled (7,835) ​ ​ 5.66 ​ Non-vested shares at end of year — ​ $ — ​
Schedule of stock options outstanding	The following table summarizes information about the Company’s stock options outstanding at December 31, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding ​ Options Exercisable ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ Remaining ​ Weighted Average ​ Number ​ Weighted Average Range of Exercise Prices ​ Outstanding ​ Contractual Life ​ Exercise Price ​ Exercisable ​ Exercise Price $13.00 to $13.99 2,034 2.1 years $ 13.51 ​ 2,034 $ 13.51 ​ $14.00 to $15.00 58,197 3.1 years ​ 14.78 58,197 ​ 14.78 ​ $13.00 to $15.00 60,231 3.1 years ​ $ 14.74 60,231 ​ $ 14.74 ​
Schedule of restricted stock activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ ​ Grant-Date Fair ​ ​ Number of RSUs ​ ​ Value Non-vested RSUs outstanding at December 31, 2016 926,931 ​ $ 13.65 ​ Granted 160,137 ​ 35.81 ​ Vested (230,903) ​ 12.01 ​ Cancelled (40,575) ​ 15.78 ​ Non-vested RSUs outstanding at December 31, 2017 815,590 ​ $ 18.35 ​ Granted 115,044 ​ 53.40 ​ Vested (330,580) ​ 13.57 ​ Cancelled (24,273) ​ 27.77 ​ Non-vested RSUs outstanding at December 31, 2018 575,781 ​ $ 27.71 ​ Granted 104,120 ​ 48.65 ​ Vested (251,853) ​ 14.79 ​ Cancelled (143,362) ​ 30.85 ​ Non-vested RSUs outstanding at December 31, 2019 284,686 ​ $ 45.21 ​
Performance stock units
Schedule of non-vested stock options	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ ​ Grant-Date ​ ​ Number of PSUs ​ ​ Fair Value Non-vested PSUs outstanding at December 31, 2016 363,993 ​ $ 14.23 Granted 119,315 ​ 35.81 Vested — ​ — Cancelled (14,732) ​ 15.00 Non-vested PSUs outstanding at December 31, 2017 468,576 ​ $ 19.70 Granted 90,264 ​ 53.41 Additional PSUs awarded from the 2015 grant 92,335 ​ 13.62 Vested (277,029) ​ 13.62 Cancelled (3,229) ​ 30.09 Non-vested PSUs outstanding at December 31, 2018 370,917 ​ $ 30.84 Granted 87,864 ​ 48.81 Additional PSUs awarded from the 2016 grant 67,853 ​ 14.80 Vested (203,582) ​ 14.80 Cancelled (89,481) ​ 34.70 Non-vested PSUs outstanding at December 31, 2019 233,571 ​ $ 45.44

Retirement Plans and Employee_2

Retirement Plans and Employee Stock Purchase Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Plans and Employee Stock Purchase Plans
Schedule of purchases made under the 2009 Employee Stock Purchase Plans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2019 ​ 2018 ​ 2017 Number of shares purchased ​ 65,148 ​ 60,950 ​ 88,362 ​ Average price of shares purchased ​ $ 48.58 ​ $ 49.85 ​ $ 33.96 ​

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Data (Unaudited)
Schedule of Quarterly Financial Data (Unaudited)	Unaudited summarized financial data by quarter for 2019 and 2018 is as follows (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2019 ​ ​ First ​ Second ​ Third ​ Fourth ​ ​ ​ ​ ​ Quarter ​ Quarter ​ Quarter ​ Quarter ​ Year Operating revenues $ 723,694 $ 744,383 $ 760,295 $ 743,591 $ 2,971,963 ​ Operating income ​ 96,419 ​ 144,093 ​ 146,441 ​ 125,305 ​ 512,258 ​ Net income (1) ​ 88,181 ​ 88,052 ​ 91,339 ​ 72,527 ​ 340,099 ​ Net income per common share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ 1.71 ​ 1.72 ​ 1.80 ​ 1.44 ​ 6.68 ​ Diluted ​ 1.69 ​ 1.71 ​ 1.79 ​ 1.43 ​ 6.62 ​ Weighted average common shares: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic: ​ 51,440 ​ 51,145 ​ 50,746 ​ 50,395 ​ 50,932 ​ Diluted: ​ 52,098 ​ 51,477 ​ 51,129 ​ 50,796 ​ 51,375 ​ (1) Net income for the first quarter of 2019 included a $46.5 million gain related to the sale of ExpressJet (see Note 13 Gain on Sale of ExpressJet for more details) and a $21.9 million special charge (see Note 8 Special Items for more details). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2018 ​ ​ First ​ Second ​ Third ​ Fourth ​ ​ ​ ​ ​ Quarter ​ Quarter ​ Quarter ​ Quarter ​ Year Operating revenues $ 783,400 $ 805,515 $ 829,275 $ 803,489 $ 3,221,679 ​ Operating income ​ 88,175 ​ 126,678 ​ 137,925 ​ 121,502 ​ 474,280 ​ Net income ​ 54,362 ​ 75,859 ​ 83,046 ​ 67,105 ​ 280,372 ​ Net income per common share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ 1.05 ​ 1.46 ​ 1.60 ​ 1.30 ​ 5.40 ​ Diluted ​ 1.03 ​ 1.43 ​ 1.57 ​ 1.28 ​ 5.30 ​ Weighted average common shares: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic: ​ 51,921 ​ 52,046 ​ 52,039 ​ 51,650 ​ 51,914 ​ Diluted: ​ 53,033 ​ 52,913 ​ 52,981 ​ 52,556 ​ 52,871 ​

Nature of Operations and Summ_4

Nature of Operations and Summary of Significant Accounting Policies - Aircraft Fleet (Details)	12 Months Ended
	Dec. 31, 2019aircraft
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of daily departures	2,300
Number of aircraft held by entity	544
CRJ 200
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	214
Number of seats on aircraft	50
CRJ 700
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	126
CRJ 700 | Minimum
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of seats on aircraft	65
CRJ 700 | Maximum
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of seats on aircraft	76
CRJ 900
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	48
CRJ 900 | Minimum
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of seats on aircraft	65
CRJ 900 | Maximum
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of seats on aircraft	76
E175
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	156
E175 | Minimum
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of seats on aircraft	65
E175 | Maximum
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of seats on aircraft	76
Delta
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	199
Percentage of aggregate capacity operated	41.20%
Delta | CRJ 200
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	84
Delta | CRJ 700
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	13
Delta | CRJ 900
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	43
Delta | E175
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	59
United
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	183
Percentage of aggregate capacity operated	37.90%
United | CRJ 200
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	99
United | CRJ 700
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	19
United | E175
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	65
American
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	69
Percentage of aggregate capacity operated	14.30%
American | CRJ 200
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	7
American | CRJ 700
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	62
Alaska
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	32
Percentage of aggregate capacity operated	6.60%
Alaska | E175
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	32
Aircraft in scheduled service
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	483
Aircraft in scheduled service | CRJ 200
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	190
Aircraft in scheduled service | CRJ 700
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	94
Aircraft in scheduled service | CRJ 900
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	43
Aircraft in scheduled service | E175
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	156
Subleased to an un-affiliated entity
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	19
Subleased to an un-affiliated entity | CRJ 200
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	4
Subleased to an un-affiliated entity | CRJ 700
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	10
Subleased to an un-affiliated entity | CRJ 900
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	5
Other
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	42
Other | CRJ 200
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	20
Other | CRJ 700
Nature of Operations and Summary of Significant Accounting Policies [Line Items]
Number of aircraft held by entity	22

Nature of Operations and Summ_5

Nature of Operations and Summary of Significant Accounting Policies - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Nature of Operations and Summary of Significant Accounting Policies
Restricted cash	$ 0	$ 0

Nature of Operations and Summ_6

Nature of Operations and Summary of Significant Accounting Policies - Marketable Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Total cash and cash equivalents	$ 87,206	$ 328,384	$ 181,792	$ 146,766
Amortized Cost	432,966	360,988
Gross unrealized holding losses		(43)
Fair market value	432,966	360,945
Total Assets Measured at Fair Value - Amortized cost	520,172	689,372
Total cash and cash equivalents and available for sale securities, fair market value	$ 520,172	689,329
Marketable Securities
Maximum period for redemption	1 year
Bonds and bond funds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 267,243	229,825
Gross unrealized holding losses		(42)
Fair market value	267,243	229,783
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	165,723	131,163
Gross unrealized holding losses		(1)
Fair market value	$ 165,723	$ 131,162

Nature of Operations and Summ_7

Nature of Operations and Summary of Significant Accounting Policies - Inventories (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Inventories
Inventory allowance	$ 15.9	$ 22.1

Nature of Operations and Summ_8

Nature of Operations and Summary of Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Aircraft, rotable spares, and spare engines | Maximum
Property and Equipment
Depreciable Life	22 years
Residual Value (as a percent)	20.00%
Ground equipment
Property and Equipment
Residual Value (as a percent)	0.00%
Ground equipment | Maximum
Property and Equipment
Depreciable Life	10 years
Office equipment
Property and Equipment
Residual Value (as a percent)	0.00%
Office equipment | Maximum
Property and Equipment
Depreciable Life	7 years
Leasehold improvements
Property and Equipment
Residual Value (as a percent)	0.00%
Leasehold improvements | Maximum
Property and Equipment
Depreciable Life	15 years
Buildings
Property and Equipment
Residual Value (as a percent)	0.00%
Buildings | Minimum
Property and Equipment
Depreciable Life	20 years
Buildings | Maximum
Property and Equipment
Depreciable Life	39 years 6 months

Nature of Operations and Summ_9

Nature of Operations and Summary of Significant Accounting Policies - Long-Lived Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Impairment of Long Lived and Intangible Assets
Property and equipment and related assets	$ 5,394,681	$ 5,005,744
Impairment of long-lived assets	$ 0	$ 0	$ 0

Nature of Operations and Sum_10

Nature of Operations and Summary of Significant Accounting Policies - Capitalized Interest (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Capitalized Interest
Capitalized interest costs	$ 1.6	$ 1.5	$ 1.4

Nature of Operations and Sum_11

Nature of Operations and Summary of Significant Accounting Policies - Flying Agreements (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)aircraft	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)aircraft	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Agreements with other airlines
Percentage of ASMs flown under fixed-fee arrangements									82.00%
Percentage of ASMs flown under pro-rate arrangements									18.00%
Revenues [Abstract]
Operating revenues | $	$ 743,591	$ 760,295	$ 744,383	$ 723,694	$ 783,400	$ 805,515	$ 829,275	$ 803,489	$ 2,971,963	$ 3,221,679	$ 3,122,592
Rental income under operating leases
Operating lease income relating to lease payments | $									27,552
Operating lease income relating to lease payments | $										3,923	3,293
Operating lease income relating to variable lease payments | $									9,608
Total operating revenues | $									2,971,963	3,221,679	3,122,592
future minimum rental income
2020 | $	32,724								32,724
2021 | $	31,344								31,344
2022 | $	24,786								24,786
2023 | $	18,530								18,530
2024 | $	18,222								18,222
Thereafter | $	54,932								54,932
Total | $	180,538								180,538
Property and equipment and related assets | $	5,394,681				5,005,744				5,394,681	5,005,744
Accounts receivable | $	83,000				64,200				$ 83,000	64,200
Alaska Capacity Purchase Agreement
future minimum rental income
Number of aircraft									32
Sky West Airlines Inc | Delta Connection Agreement
future minimum rental income
Agreement term									4 years 1 month 6 days
Sky West Airlines Inc | Delta Connection Prorate Agreement
future minimum rental income
Notice period for termination of agreement									30 days
Sky West Airlines Inc | United Express Agreements
future minimum rental income
Agreement term									4 years 3 months 18 days
Sky West Airlines Inc | United Express Prorate Agreement
future minimum rental income
Notice period for termination of agreement									120 days
Sky West Airlines Inc | American Prorate Agreement
future minimum rental income
Notice period for termination of agreement									120 days
Third Party Lease
future minimum rental income
Property and equipment and related assets | $	$ 97,000								$ 97,000
CRJ 200
future minimum rental income
Number of seats on aircraft									50
CRJ 200 | American Prorate Agreement
future minimum rental income
Number of aircraft									7
CRJ 200 | Sky West Airlines Inc | Delta Connection Agreement
future minimum rental income
Number of aircraft									55
CRJ 200 | Sky West Airlines Inc | Delta Connection Prorate Agreement
future minimum rental income
Number of aircraft									29
CRJ 200 | Sky West Airlines Inc | United Express Agreements
future minimum rental income
Number of aircraft									68
CRJ 200 | Sky West Airlines Inc | United Express Prorate Agreement
future minimum rental income
Number of aircraft									31
CRJ 700 | Minimum
future minimum rental income
Number of seats on aircraft									65
CRJ 700 | Maximum
future minimum rental income
Number of seats on aircraft									76
CRJ 700 | American Capacity Purchase Agreement
future minimum rental income
Number of aircraft									62
Agreement term									4 years 1 month 6 days
CRJ 700 | Sky West Airlines Inc | Delta Connection Agreement
future minimum rental income
Number of aircraft									13
CRJ 700 | Sky West Airlines Inc | United Express Agreements
future minimum rental income
Number of aircraft									19
CRJ 700 | American
future minimum rental income
Number of aircraft									10
Number of aircrafts to be placed in service	2								2
CRJ 900 | Minimum
future minimum rental income
Number of seats on aircraft									65
CRJ 900 | Maximum
future minimum rental income
Number of seats on aircraft									76
CRJ 900 | Sky West Airlines Inc | Delta Connection Agreement
future minimum rental income
Number of aircraft									43
CRJ 900 | Delta
future minimum rental income
Number of aircraft									1
Agreement term									9 years
E175 | Minimum
future minimum rental income
Number of seats on aircraft									65
E175 | Maximum
future minimum rental income
Number of seats on aircraft									76
E175 | Alaska Capacity Purchase Agreement
future minimum rental income
Agreement term									9 years 2 months 12 days
E175 | Sky West Airlines Inc | Delta Connection Agreement
future minimum rental income
Number of aircraft									59
Number of additional aircraft placed into service									6
E175 | Sky West Airlines Inc | United Express Agreements
future minimum rental income
Number of aircraft									65
E175 | Sky West Airlines Inc | American Capacity Purchase Agreement
future minimum rental income
Number of additional aircraft placed into service									20
Flying agreements
Revenues [Abstract]
Operating revenues | $									$ 2,889,265	3,169,520	3,078,297
Rental income under operating leases
Total operating revenues | $									2,889,265	3,169,520	3,078,297
future minimum rental income
Accounts receivable | $	$ 58,800				$ 52,700				58,800	52,700
Flight operations
Revenues [Abstract]
Operating revenues | $									1,538,062	1,856,253	1,805,510
Aircraft lease
Revenues [Abstract]
Operating revenues | $									830,247	814,518	834,366
Prorate agreements
Revenues [Abstract]
Operating revenues | $									520,956	498,749	438,421
Airport customer service revenue
Revenues [Abstract]
Operating revenues | $									45,538	48,236	41,002
Airport customer service and other
Rental income under operating leases
Total operating revenues | $									$ 82,698	$ 52,159	$ 44,295

Nature of Operations and Sum_12

Nature of Operations and Summary of Significant Accounting Policies - Net Income Per Common Share and Fair Value (Details) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares	Sep. 30, 2019USD ($)$ / sharesshares	Jun. 30, 2019USD ($)$ / sharesshares	Mar. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Sep. 30, 2018USD ($)$ / sharesshares	Jun. 30, 2018USD ($)$ / sharesshares	Mar. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2019USD ($)segment$ / sharesshares	Dec. 31, 2018USD ($)segment$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares
Net Income Per Common Share
Number of outstanding units not included in computation of Diluted EPS (in shares)									150,000	207,000	284,000
Numerator:
Net income | $	$ 72,527	$ 91,339	$ 88,052	$ 88,181	$ 54,362	$ 75,859	$ 83,046	$ 67,105	$ 340,099	$ 280,372	$ 428,907
Denominator:
Basic earnings per share weighted average shares (in shares)	50,395,000	50,746,000	51,145,000	51,440,000	51,921,000	52,046,000	52,039,000	51,650,000	50,932,000	51,914,000	51,804,000
Dilution due to stock options and restricted stock units (in shares)									443,000	957,000	1,296,000
Diluted earnings per share weighted average shares	50,796,000	51,129,000	51,477,000	52,098,000	53,033,000	52,913,000	52,981,000	52,556,000	51,375,000	52,871,000	53,100,000
Basic earnings per share (in dollars per share) | $ / shares	$ 1.44	$ 1.80	$ 1.72	$ 1.71	$ 1.05	$ 1.46	$ 1.60	$ 1.30	$ 6.68	$ 5.40	$ 8.28
Diluted earnings per share (in dollars per share) | $ / shares	$ 1.43	$ 1.79	$ 1.71	$ 1.69	$ 1.03	$ 1.43	$ 1.57	$ 1.28	$ 6.62	$ 5.30	$ 8.08
Fair Value of Financial Instruments
Fair value of long-term debt | $	$ 3,049,100				$ 3,157,300				$ 3,049,100	$ 3,157,300
Total long-term debt | $	$ 3,017,523				$ 3,185,438				$ 3,017,523	$ 3,185,438
Segment Reporting
Number of operating segments | segment										3
Number of reporting segments | segment									2

Nature of Operations and Sum_13

Nature of Operations and Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - Adjustment - Topic 326 $ in Millions	Jan. 01, 2020USD ($)
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Credit loss	$ 7
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Credit loss	$ 12

Segment Reporting (Details)

Segment Reporting (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)segment	Dec. 31, 2018USD ($)segment	Dec. 31, 2017USD ($)
Segment Reporting
Number of operating segments | segment										3
Number of reporting segments | segment									2
Operating revenues	$ 743,591	$ 760,295	$ 744,383	$ 723,694	$ 783,400	$ 805,515	$ 829,275	$ 803,489	$ 2,971,963	$ 3,221,679	$ 3,122,592
Operating expense									2,459,705	2,747,399	2,734,393
Depreciation and amortization expense									368,098	334,589	292,768
Special items		$ 21,900							21,869
Interest expense									127,755	120,409	104,925
Segment profit (loss)									384,503	353,871	283,274
Identifiable intangible assets, other than goodwill											4,896
Total assets	6,657,129				6,313,212				6,657,129	6,313,212	5,474,400
Capital expenditures (including non-cash)									846,470	1,156,276	689,398
SkyWest Airlines
Segment Reporting
Operating revenues									2,478,681	2,346,251	2,092,368
Operating expense									2,214,632	2,022,560	1,807,540
Depreciation and amortization expense									168,246	155,511	134,563
Special items									18,508
Interest expense									13,525	17,021	21,544
Segment profit (loss)									250,524	306,670	263,284
Total assets	2,728,964				2,531,707				2,728,964	2,531,707	2,245,051
Capital expenditures (including non-cash)									270,191	149,731	124,955
ExpressJet Airlines Inc
Segment Reporting
Operating revenues									24,050	564,202	790,282
Operating expense									28,690	577,608	818,683
Depreciation and amortization expense									971	37,290	51,982
Special items									3,361
Interest expense										2,340	4,127
Segment profit (loss)									(4,640)	(15,746)	(32,528)
Identifiable intangible assets, other than goodwill											4,896
Total assets					279,303					279,303	599,122
Capital expenditures (including non-cash)										10,137	14,278
SkyWest Leasing
Segment Reporting
Operating revenues									469,232	311,226	239,942
Operating expense									216,383	147,231	108,170
Depreciation and amortization expense									198,881	141,788	106,223
Interest expense									114,230	101,048	79,254
Segment profit (loss)									138,619	62,947	52,518
Total assets	$ 3,928,165				$ 3,502,202				3,928,165	3,502,202	2,630,227
Capital expenditures (including non-cash)									$ 576,279	$ 996,408	$ 550,165

Long-term Debt (Details)

Long-term Debt (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)aircraft	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Total long-term debt	$ 3,017,523	$ 3,185,438
Current portion of long-term debt	(367,954)	(354,072)
Less long-term portion of unamortized debt issue cost, net	(20,580)	(21,598)
Long-term debt, net of current maturities and debt issue costs	2,628,989	2,809,768
Current portion of long-term debt	367,954	354,072
Less current portion of unamortized debt issue cost, net	(3,828)	(3,866)
Current portion of long-term debt, net of debt issue costs	364,126	350,206
Debt issued to purchase of aircraft	$ 14,500
Effective interest rate (as a percent)	4.20%
Aggregate amounts of principal maturities of long-term debt
2020	$ 367,954
2021	352,005
2022	365,907
2023	374,906
2024	327,630
Thereafter	1,229,121
Repayment of debt in cash	30,100	43,500
Total repayment of debt	30,100	43,500
Letters of credit	8,800	9,700
Current borrowing capacity	66,200	65,300
Letters of credit and surety bonds outstanding with various banks and surety institutions	$ 61,700	78,700
E175
Debt Instrument [Line Items]
Number of aircraft delivered | aircraft	10
Purchase of aircraft financed through long-term debt	$ 200,000
Debt instrument, term	12 years
Purchased, previously-leased aircraft
Debt Instrument [Line Items]
Interest rate (as a percent)	2.00%
Debt instrument, term	18 months
Number of aircraft purchased | aircraft	2
Minimum | E175
Debt Instrument [Line Items]
Interest rate (as a percent)	3.40%
Maximum | E175
Debt Instrument [Line Items]
Interest rate (as a percent)	4.10%
Notes payable to banks, due in semi-annual installments, variable interest based on LIBOR, or with an interest rate of 4.00% through 2019, secured by aircraft
Debt Instrument [Line Items]
Interest rate (as a percent)	4.00%
Total long-term debt		6,429
Notes payable to a financing company, due in semi-annual installments, with a fixed interest rate of 3.25% through 2021, secured by aircraft
Debt Instrument [Line Items]
Interest rate (as a percent)	3.25%
Total long-term debt	$ 18,412	36,324
Notes payable to banks, due in semi-annual installments plus interest at 6.10% to 6.51% through 2021, secured by aircraft
Debt Instrument [Line Items]
Total long-term debt	$ 22,557	41,592
Notes payable to banks, due in semi-annual installments plus interest at 6.10% to 6.51% through 2021, secured by aircraft | Minimum
Debt Instrument [Line Items]
Interest rate (as a percent)	6.10%
Notes payable to banks, due in semi-annual installments plus interest at 6.10% to 6.51% through 2021, secured by aircraft | Maximum
Debt Instrument [Line Items]
Interest rate (as a percent)	6.51%
Notes payable to banks, due in monthly installments, plus interest at 1.95% to 6.86% through 2029, secured by aircraft
Debt Instrument [Line Items]
Total long-term debt	$ 438,878	476,369
Notes payable to banks, due in monthly installments, plus interest at 1.95% to 6.86% through 2029, secured by aircraft | Minimum
Debt Instrument [Line Items]
Interest rate (as a percent)	1.95%
Notes payable to banks, due in monthly installments, plus interest at 1.95% to 6.86% through 2029, secured by aircraft | Maximum
Debt Instrument [Line Items]
Interest rate (as a percent)	6.86%
Notes payable to banks, due in quarterly installments, plus interest at 3.39% to 5.08% through 2031, secured by aircraft
Debt Instrument [Line Items]
Total long-term debt	$ 2,537,676	2,621,416
Notes payable to banks, due in quarterly installments, plus interest at 3.39% to 5.08% through 2031, secured by aircraft | Minimum
Debt Instrument [Line Items]
Interest rate (as a percent)	3.39%
Notes payable to banks, due in quarterly installments, plus interest at 3.39% to 5.08% through 2031, secured by aircraft | Maximum
Debt Instrument [Line Items]
Interest rate (as a percent)	5.08%
Notes payable to banks due in monthly installments, interest based on LIBOR interest at 3.30% through 2019, secured by spare engines
Debt Instrument [Line Items]
Interest rate (as a percent)	3.30%
Total long-term debt		3,308
Line of credit
Aggregate amounts of principal maturities of long-term debt
Maximum borrowing capacity	$ 75,000	75,000
Amount outstanding	$ 0	$ 0
LIBOR | Line of credit
Debt Instrument [Line Items]
Basis spread on variable rate	2.50%

Income Taxes - Provision (Detai

Income Taxes - Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current tax provision (benefit):
Federal	$ (4,395)	$ (21,598)	$ 5,853
State	891	1,465	180
Foreign		1,575
Total current tax provision (benefit)	(3,504)	(18,558)	6,033
Deferred tax provision (benefit):
Federal	95,655	92,250	(166,890)
State	14,055	12,250	20,133
Total deferred tax provision (benefit)	109,710	104,500	(146,757)
Provision (benefit) for income taxes	$ 106,206	$ 85,942	$ (140,724)

Income Taxes - Reconciliation (

Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statutory Federal income tax rate (as a percent)	21.00%	21.00%	35.00%
Reconciliation
Computed provision for income taxes at the statutory rate	$ 93,724	$ 76,926	$ 100,864
State income tax provision, net of federal income tax benefit	15,645	12,711	7,778
Non-deductible expenses	3,934	1,956	3,230
Valuation allowance changes affecting the provision for income taxes	(517)	(1,187)	505
Foreign income taxes, net of federal & state benefit		1,192
Excess tax benefits from share based compensation	(3,525)	(4,548)	(5,377)
Revaluation of net deferred taxes for the Tax Cuts and Jobs Act of 2017			(246,845)
Other, net	(3,055)	(1,108)	(879)
Provision (benefit) for income taxes	106,206	85,942	(140,724)
Deferred tax assets:
Accrued benefits	20,848	32,462
Net operating loss carryforward	358,685	344,375
AMT credit carryforward	4,397	15,744
Aircraft credits	9,114	35,924
Accrued reserves and other	17,225	18,710
Total deferred tax assets	410,269	447,215
Valuation allowance	(892)	(9,455)
Deferred tax liabilities:
Accelerated depreciation	(1,032,957)	(955,919)
Total deferred tax liabilities	(1,032,957)	(955,919)
Net deferred tax liability	(623,580)	(518,159)
Accounting Standards Update 2016-09
Reconciliation
Benefit from share-based compensation	3,500	4,500	5,400
ExpressJet | State
Reconciliation
Valuation allowance	$ 500	$ 1,200	$ 500

Income Taxes - Net Operating Lo

Income Taxes - Net Operating Losses and Tax Rates (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net operating losses
Statutory Federal income tax rate (as a percent)	21.00%	21.00%	35.00%
Alternative minimum tax credit which does not expire	$ 4.4	$ 8.8
Tax credit recovery period	2 years
Federal
Net operating losses
Operating loss carryforward	$ 1,581.1	1,504.9
Estimated effective tax rate on net operating losses	21.00%
State
Net operating losses
Operating loss carryforward	$ 766.4	$ 562
Estimated effective tax rate on net operating losses	3.36%

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details)	12 Months Ended
	Dec. 31, 2019USD ($)
Income Taxes
Unrecognized tax benefits at the beginning of year	$ 14,553,000
Gross increases - prior year tax positions	67,000
Unrecognized tax benefits at end of year	14,620,000
Interest and penalties in year-end balance	67,000
Interest expense related to uncertain tax positions	$ 67,000

Commitments and Contingencies (

Commitments and Contingencies (Details)	12 Months Ended
	Dec. 31, 2019USD ($)employee	Dec. 31, 2018USD ($)	Dec. 31, 2017
Concentration Risk and Significant Customers
Accrued workers' compensation liability | $	$ 23,900,000	$ 42,000,000
Allowance for doubtful accounts | $	$ 18,000	$ 158,000
Revenue from rights, concentration risk | Customer concentration risk | Delta, United, and Continental Combined
Concentration Risk and Significant Customers
Concentration risk (as a percent)	77.60%	81.40%	82.90%
Full-time equivalent number of employees | Labor force concentration risk
Concentration Risk and Significant Customers
Number of employees | employee	13,700
SkyWest Airlines | Full-time equivalent number of employees | Unionized employees
Concentration Risk and Significant Customers
Approximate number of active employees | employee	0

Leases - Leases (Details)

Leases - Leases (Details) $ in Thousands	Jan. 01, 2019USD ($)	Sep. 30, 2019USD ($)aircraft	Mar. 31, 2019USD ($)aircraft	Dec. 31, 2019USD ($)item	Dec. 31, 2018USD ($)
Lessee, Lease, Description [Line Items]
Number of aircraft leased | item				94
Operating lease right-of-use assets				$ 336,009
Current maturities of lease liabilities				94,806
Noncurrent operating leases				259,237
Operating leases				$ 75,400
Weighted-average remaining lease term: Operating leases				6 years 10 months 2 days
Weighted-average discount rate: Operating leases				6.40%
Lease costs
Operating lease cost				$ 104,011	$ 185,337
Variable and short-term lease cost				5,232	5,143
Sublease income				(1,436)
Total lease cost				$ 107,807	$ 190,480
Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft acquired | aircraft		4	52
Payments for acquired aircraft		$ 30,000	$ 111,700
Impairment adjustment on retained earnings	$ 13,100
Aircraft | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term				1 year
Aircraft | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term				10 years
Airport Facilities | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term				1 month
Airport Facilities | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term				37 years

Leases - Future Minimum Rental

Leases - Future Minimum Rental Payment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Future minimum rental payments required under operating leases
2020	$ 94,806
2021	84,285
2022	73,960
2023	68,581
2024	27,282
Thereafter	94,746
Total	443,660
Total rental expense for non-cancelable aircraft operating leases		$ 154,900	$ 215,800
Total rental expense for non-cancelable aircraft operating leases	72,000
Minimum rental expense for airport station rents		19,600	$ 30,300
Minimum rental expense for airport station rents	$ 23,100
Future minimum rental payments required under operating leases
2019		87,256
2020		101,741
2021		90,787
2022		72,593
2023		65,749
Thereafter		59,820
Total future lease obligations		$ 477,946

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Measurements
Marketable securities	$ 432,966	$ 360,945
Total assets measured at fair value	520,172	689,372
Fair Value of Financial Instruments
Fair value of long-term debt	3,049,100	3,157,300
Recurring | Fair value
Fair Value Measurements
Marketable securities	432,966	360,945
Cash, Cash Equivalents and Restricted Cash	87,206	328,384
Total assets measured at fair value	520,172	689,329
Recurring | Fair value | Bonds and bond funds
Fair Value Measurements
Marketable securities	267,243	229,783
Recurring | Fair value | Commercial paper
Fair Value Measurements
Marketable securities	165,723	131,162
Recurring | Level 1
Fair Value Measurements
Cash, Cash Equivalents and Restricted Cash	87,206	328,384
Total assets measured at fair value	87,206	328,384
Recurring | Level 2
Fair Value Measurements
Marketable securities	432,966	360,945
Total assets measured at fair value	432,966	360,945
Recurring | Level 2 | Bonds and bond funds
Fair Value Measurements
Marketable securities	267,243	229,783
Recurring | Level 2 | Commercial paper
Fair Value Measurements
Marketable securities	$ 165,723	$ 131,162

Special Items (Details)

Special Items (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019
Special Items
Parts credit		$ 18,508
Employee severance		3,361
Total Special items	$ 21,900	$ 21,869

Capital Transactions - Preferre

Capital Transactions - Preferred Stock (Details) - shares	Dec. 31, 2019	Dec. 31, 2018
Preferred Stock
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock outstanding (in shares)	0

Capital Transactions - Stock Co

Capital Transactions - Stock Compensation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	May 04, 2010
Share-Based Compensation
Performance period	90 days
Compensation expenses
Stock based compensation expense	$ 10,274,000	$ 13,105,000	$ 10,580,000
Employee severance related costs	7,900,000
Forfeiture credit partially offset	$ 4,500,000
Director
Share-Based Compensation
Granted (in shares)	18,576	15,165
Granted (in dollars per share)	$ 48.45	$ 53.40	$ 35.81
Number of shares
Granted (in shares)	18,576	15,165
Weighted Average Grant-Date Fair Value
Granted (in dollars per share)	$ 48.45	$ 53.40	$ 35.81
Number of Options
Granted (in shares)			22,617
Non-vested stock options
Granted (in shares)			22,617
Restricted stock grants and performance stock units
Compensation expenses
Total unrecognized compensation cost				$ 10,000,000
Unrecognized compensation cost recognized over a weighted average period (in years)	1 month 21 days
Employee stock options
Share-Based Compensation
Options outstanding (in shares)	300,580	458,103	458,103	60,231	300,580
Compensation expenses
Period from grant date after which stock options become exercisable, minimum (in months)	6 months
Period from grant date within which incentive stock options are exercisable, maximum (in years)	7 years
Number of Options
Outstanding at the beginning of the period (in shares)	300,580	458,103	819,981
Exercised (in shares)	(232,514)	(157,523)	(356,209)
Cancelled (in shares)	(7,835)		(5,669)
Outstanding at the end of the period (in shares)	60,231	300,580	458,103
Exercisable (in shares)				60,231	235,672
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 13.70	$ 13.73	$ 13.58
Exercised (in dollars per share)	13.36	13.80	13.36
Cancelled (in dollars per share)	15.86		14.33
Outstanding at the end of the period (in dollars per share)	$ 14.74	$ 13.70	$ 13.73
Exercisable (in dollars per share)				$ 14.74	$ 13.36
Weighted Average Remaining Contractual Term
Outstanding, Weighted Average Remaining Contractual Term (in years)	3 years 1 month 6 days	3 years
Exercisable, Weighted Average Remaining Contractual Term (in years)	3 years 1 month 6 days	2 years 8 months 12 days
Aggregate Intrinsic Value
Average intrinsic value of shares outstanding				$ 3,005,100	$ 9,249,400
Average intrinsic value of shares exercisable				$ 3,005,100	$ 7,330,700
Total intrinsic value of options exercised	$ 10,500,000	$ 7,100,000	$ 9,940,000
Non-vested stock options
Non-vested shares at beginning of year (in shares)	64,908
Vested (in shares)	(57,073)
Cancelled (in shares)	(7,835)
Non-vested shares at end of year (in shares)		64,908
Weighted Average Grant-Date Fair Value
Non-vested shares at beginning of year (in dollars per share)	$ 5.32
Vested (in dollars per share)	5.27
Cancelled (in dollars per share)	$ 5.66
Non-vested shares at end of year (in dollars per share)		$ 5.32
Performance stock units
Share-Based Compensation
Granted (in shares)	87,864	90,264	119,315
Granted (in dollars per share)	$ 48.81	$ 53.41	$ 35.81
Performance period	3 years
Number of shares
Nonvested sharess at the beginning of the period (in shares)	370,917	468,576	363,993
Granted (in shares)	87,864	90,264	119,315
Additional shares awarded from the 2015 grant	67,853		92,335
Vested (in shares)	(203,582)	(277,029)
Cancelled (in shares)	(89,481)	(3,229)	(14,732)
Nonvested shares at the end of the period (in shares)	233,571	370,917	468,576
Weighted Average Grant-Date Fair Value
Nonvested shares at the beginning of the period (in dollars per share)	$ 30.84	$ 19.70	$ 14.23
Granted (in dollars per share)	48.81	53.41	35.81
Additional shares awarded from the 2015 grant (in dollars per share)	14.80		13.62
Vested (in dollars per share)	14.80	13.62
Cancelled (in dollars per share)	34.70	30.09	15
Nonvested shares at the end of the period (in dollars per share)	$ 45.44	$ 30.84	$ 19.70
Performance stock units | Maximum
Share-Based Compensation
Award percentage	200.00%	200.00%	200.00%
Performance stock units | Minimum
Share-Based Compensation
Award percentage	0.00%	0.00%	0.00%
Restricted stock units
Share-Based Compensation
Granted (in shares)	104,120	115,044	160,137
Granted (in dollars per share)	$ 48.65	$ 53.40	$ 35.81
Number of shares
Nonvested sharess at the beginning of the period (in shares)	575,781	815,590	926,931
Granted (in shares)	104,120	115,044	160,137
Vested (in shares)	(251,853)	(330,580)	(230,903)
Cancelled (in shares)	(143,362)	(24,273)	(40,575)
Nonvested shares at the end of the period (in shares)	284,686	575,781	815,590
Weighted Average Grant-Date Fair Value
Nonvested shares at the beginning of the period (in dollars per share)	$ 27.71	$ 18.35	$ 13.65
Granted (in dollars per share)	48.65	53.40	35.81
Vested (in dollars per share)	14.79	13.57	12.01
Cancelled (in dollars per share)	30.85	27.77	15.78
Nonvested shares at the end of the period (in dollars per share)	$ 45.21	$ 27.71	$ 18.35
Long Term Incentive Plan 2010
Share-Based Compensation
Number of shares authorized						4,500,000
Shares remaining available for future issuance				4,400,000
Long Term Incentive Plan 2010 | Restricted stock units
Share-Based Compensation
Vesting period	3 years
Granted (in dollars per share)	$ 48.65
Weighted Average Grant-Date Fair Value
Granted (in dollars per share)	$ 48.65
Long Term Incentive Plan 2010 | Restricted stock units | Director
Share-Based Compensation
Granted (in shares)	104,120
Number of shares
Granted (in shares)	104,120

Capital Transactions - Informat

Capital Transactions - Information About Stock Options Outstanding (Details) - Employee stock options	12 Months Ended
	Dec. 31, 2019$ / sharesshares
$13.00 to $13.99
Stock options, exercise price
Exercise price range, low end of range (in dollars per share)	$ 13
Exercise price range, high end of range (in dollars per share)	$ 13.99
Options Outstanding
Number of options outstanding (in shares) | shares	2,034
Options outstanding, Weighted Average Remaining Contractual Life	2 years 1 month 6 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 13.51
Options Exercisable
Number of options Exercisable (in shares) | shares	2,034
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 13.51
$14.00 to $15.00
Stock options, exercise price
Exercise price range, low end of range (in dollars per share)	14
Exercise price range, high end of range (in dollars per share)	$ 15
Options Outstanding
Number of options outstanding (in shares) | shares	58,197
Options outstanding, Weighted Average Remaining Contractual Life	3 years 1 month 6 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 14.78
Options Exercisable
Number of options Exercisable (in shares) | shares	58,197
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 14.78
$13.00 to $15.00
Stock options, exercise price
Exercise price range, low end of range (in dollars per share)	13
Exercise price range, high end of range (in dollars per share)	$ 15
Options Outstanding
Number of options outstanding (in shares) | shares	60,231
Options outstanding, Weighted Average Remaining Contractual Life	3 years 1 month 6 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 14.74
Options Exercisable
Number of options Exercisable (in shares) | shares	60,231
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 14.74

Retirement Plans and Employee_3

Retirement Plans and Employee Stock Purchase Plans - Retirement Plans (Details) - SkyWest Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Plans
Service period required to be completed to be eligible to participate in plan	90 days
Required age for an employee to be eligible to participate in plan	18 years
Percentage of employer matching contribution based on length of service	100.00%
Minimum benefit plan percentage of participants compensation eligible for employer matching contribution based on position and years of service	2.00%
Maximum benefit plan percentage of participants compensation eligible for employer matching contribution based on position and years of service	12.00%
Company's combined contributions	$ 40.7	$ 35.6	$ 26.1

Retirement Plans and Employee_4

Retirement Plans and Employee Stock Purchase Plans - Employee Stock Purchase Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Stock Purchase Plans
Service period required to be completed for an employee to be eligible to participate in plan, minimum	90 days
Ownership interest in Company common stock to disqualify employee from participation in plan, maximum (as a percent)	5.00%
Maximum percentage of base salary which can be contributed by the employees	15.00%
Maximum amount of base salary which can be contributed annually by the employees	$ 25,000
Discount rate at which common stock can be purchased by the plan participant (as a percent)	5.00%
Summary of purchases made under the 2010 and 1995 Employee Stock Purchase Plans
Number of shares purchased	65,148	60,950	88,362
Average price of shares purchased (in dollars per share)	$ 48.58	$ 49.85	$ 33.96
2009 Stock Purchase Plan
Summary of purchases made under the 2010 and 1995 Employee Stock Purchase Plans
Stock based compensation expense	$ 0	$ 0	$ 0

Stock Repurchase (Details)

Stock Repurchase (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Repurchase
Common stock authorized for repurchase, maximum (in shares)	250
Common stock remaining number of shares authorized to repurchase	159.6
Common stock repurchased (in shares)	1.7	1	0.5
Common stock repurchased, value	$ 94.6	$ 54.4	$ 20
Weighted average price per share of common stock (in dollars per share)	$ 56.86	$ 56.25	$ 41.36
Payment of income tax obligation on employee equity awards	$ 9.3	$ 13.6	$ 5.1

Related-Party Transactions (Det

Related-Party Transactions (Details) - USD ($)	Jun. 13, 2019	Dec. 31, 2019
Related Party Transactions
Common stock purchased and cancelled (in shares)	268,025
Share price (in dollars per share)	$ 60.24
Period of Trading Days Prior to Repurchase to Calculate Volume Weighted Average Closing Price	5 days
Affiliated entity
Related Party Transactions
Purchase from related party		$ 93,540

Gain on Sale of ExpressJet (Det

Gain on Sale of ExpressJet (Details) $ in Thousands	Jan. 22, 2019USD ($)aircraft	Jan. 11, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Gain on sale	$ 46,500		$ 46,500	$ 46,525
Interest rate (as a percent)	6.85%
Asset Purchase Agreement | ExpressJet
Proceeds from sale of equipment		$ 60,800
Stock Purchase Agreement | ExpressJet
Cash received from stock sale	$ 18,800
Amount loaned to Kair Enterprises, Inc	$ 26,000
Number of aircraft in early lease buyout | aircraft	16

Investment in Other Companies (

Investment in Other Companies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)engine
Number of spare engines sold to Aero Engines | engine	14
Aero Engines, LLC.
Payments to acquire interest in joint venture	$ 22,300
Investment ownership (as a percent)	75.00%
Number of spare engines purchased | engine	14
Long-term debt	$ 0
Investment balance in Aero Engines	23,900
Additional interest in Joint venture	1,000
Company's portion of income generated by Aero Engines	$ 600

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 22, 2019	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Data (Unaudited)
Operating revenues		$ 743,591	$ 760,295	$ 744,383	$ 723,694	$ 783,400	$ 805,515	$ 829,275	$ 803,489	$ 2,971,963	$ 3,221,679	$ 3,122,592
Operating income		125,305	146,441	144,093	96,419	88,175	126,678	137,925	121,502	512,258	474,280	388,199
Net income		$ 72,527	$ 91,339	$ 88,052	$ 88,181	$ 54,362	$ 75,859	$ 83,046	$ 67,105	$ 340,099	$ 280,372	$ 428,907
Net income per common share:
Basic (in dollars per share)		$ 1.44	$ 1.80	$ 1.72	$ 1.71	$ 1.05	$ 1.46	$ 1.60	$ 1.30	$ 6.68	$ 5.40	$ 8.28
Diluted (in dollars per share)		$ 1.43	$ 1.79	$ 1.71	$ 1.69	$ 1.03	$ 1.43	$ 1.57	$ 1.28	$ 6.62	$ 5.30	$ 8.08
Weighted average common shares:
Basic (in shares)		50,395,000	50,746,000	51,145,000	51,440,000	51,921,000	52,046,000	52,039,000	51,650,000	50,932,000	51,914,000	51,804,000
Diluted (in shares)		50,796,000	51,129,000	51,477,000	52,098,000	53,033,000	52,913,000	52,981,000	52,556,000	51,375,000	52,871,000	53,100,000
Gain on sale of subsidiary	$ 46,500				$ 46,500					$ 46,525
Special items			$ 21,900							$ 21,869

SCHEDULE II -VALUATION AND QUAL

SCHEDULE II -VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	$ 22,299	$ 17,255	$ 40,670
Additions Charged to Costs and Expenses		5,044
Deductions	(6,391)		(23,415)
Balance at End of Year	15,908	22,299	17,255
Allowance for inventory obsolescence
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	22,141	17,098	40,497
Additions Charged to Costs and Expenses		5,043
Deductions	(6,251)		(23,399)
Balance at End of Year	15,890	22,141	17,098
Allowance for doubtful accounts receivable
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	158	157	173
Additions Charged to Costs and Expenses		1
Deductions	(140)		(16)
Balance at End of Year	$ 18	$ 158	$ 157