SkyWest (SKYW) 10-Q 5 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2019
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
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
Title of 12(b) Security	Common Stock, No Par Value
Trading Symbol	SKYW
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		50,421,364
Entity Central Index Key	0000793733
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 307,909	$ 328,384
Marketable Securities	263,597	360,945
Income tax receivable	24,478	25,936
Receivables, net	77,532	64,194
Inventories, net	111,941	127,690
Prepaid aircraft rents		87,031
Other current assets	24,932	26,614
Total current assets	810,389	1,020,794
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	6,903,732	6,433,916
Deposits on aircraft	50,906	42,012
Buildings and ground equipment	248,405	291,544
Total property and equipment, gross	7,203,043	6,767,472
Less-accumulated depreciation and amortization	(1,906,345)	(1,761,728)
Total property and equipment, net	5,296,698	5,005,744
OTHER ASSETS:
Operating lease right-of-use assets	326,700
Long-term prepaid assets		181,830
Other assets	163,872	104,844
Total other assets	490,572	286,674
Total assets	6,597,659	6,313,212
CURRENT LIABILITIES:
Current maturities of long-term debt	362,582	350,206
Accounts payable	328,854	331,982
Accrued salaries, wages and benefits	129,507	161,606
Current maturities of operating lease liabilities	87,472
Taxes other than income taxes	18,708	16,024
Other current liabilities	34,416	65,008
Total current liabilities	961,539	924,826
LONG-TERM DEBT, net of current maturities	2,622,236	2,809,768
DEFERRED INCOME TAXES PAYABLE	596,897	518,159
DEFERRED AIRCRAFT CREDITS		29,308
NONCURRENT OPERATING LEASE LIABILITIES	254,258
OTHER LONG-TERM LIABILITIES	46,469	66,870
COMMITMENTS AND CONTINGENCIES (Note 6)
STOCKHOLDERS' EQUITY:
Preferred stock, 5,000,000 shares authorized; none issued
Common stock, no par value, 120,000,000 shares authorized; 81,742,904 and 81,239,289 shares issued, respectively	684,541	690,910
Retained earnings	2,012,691	1,776,585
Treasury stock, at cost, 31,252,786 and 29,850,999 shares, respectively	(580,972)	(503,182)
Accumulated other comprehensive loss		(32)
Total stockholders' equity	2,116,260	1,964,281
Total liabilities and stockholders' equity	$ 6,597,659	$ 6,313,212

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 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	81,742,904	81,239,289
Treasury stock, at cost, shares	31,252,786	29,850,999

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
OPERATING REVENUES:
Total operating revenues	$ 760,295	$ 829,275	$ 2,228,372	$ 2,418,190
OPERATING EXPENSES:
Salaries, wages and benefits	251,414	301,378	752,768	901,775
Depreciation and amortization	92,795	86,088	272,929	246,386
Special items			21,869
Other operating expenses	59,577	68,859	184,634	206,511
Total operating expenses	613,854	691,350	1,841,419	2,065,412
OPERATING INCOME	146,441	137,925	386,953	352,778
OTHER INCOME (EXPENSE):
Interest income	3,542	2,283	11,081	5,692
Interest expense	(31,606)	(31,440)	(96,884)	(86,485)
Other income (expense), net	361	1,157	47,367	3,470
Total other expense, net	(27,703)	(28,000)	(38,436)	(77,323)
INCOME BEFORE INCOME TAXES	118,738	109,925	348,517	275,455
PROVISION FOR INCOME TAXES	27,399	26,879	80,945	62,189
NET INCOME	$ 91,339	$ 83,046	$ 267,572	$ 213,266
BASIC EARNINGS PER SHARE (in dollars per share)	$ 1.80	$ 1.60	$ 5.24	$ 4.10
DILUTED EARNINGS PER SHARE (in dollars per share)	$ 1.79	$ 1.57	$ 5.19	$ 4.03
Weighted average common shares:
Basic (in shares)	50,746	52,039	51,111	52,002
Diluted (in shares)	51,129	52,981	51,568	52,976
COMPREHENSIVE INCOME:
Net income	$ 91,339	$ 83,046	$ 267,572	$ 213,266
Net unrealized appreciation on debt securities, net of taxes		(2)	32	32
TOTAL COMPREHENSIVE INCOME	91,339	83,044	267,604	213,298
Flying agreements
OPERATING REVENUES:
Total operating revenues	738,838	816,057	2,164,173	2,377,659
Airport customer service and other
OPERATING REVENUES:
Total operating revenues	21,457	13,218	64,199	40,531
Aircraft maintenance, materials and repairs
OPERATING REVENUES:
Total operating revenues	133,521	142,285	376,572	423,665
Aircraft fuel
OPERATING REVENUES:
Total operating revenues	31,063	30,258	87,570	87,208
Airport related expenses
OPERATING REVENUES:
Total operating revenues	27,808	25,655	89,237	80,852
Aircraft rentals
OPERATING REVENUES:
Total operating revenues	$ 17,676	$ 36,827	$ 55,840	$ 119,015

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, 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		$ 213,266			213,266
Net unrealized depreciation on marketable securities, net of taxes				32	32
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
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 associated with equity awards, net of forfeitures	$ 10,363				10,363
Treasury shares acquired from vested employee stock awards for income tax withholdings			(25,164)		(25,164)
Treasury shares acquired from vested employee stock awards for income tax withholdings (in shares)		(428)
Treasury stock purchases			(13,556)		(13,556)
Treasury stock purchases (in shares)		(239)
Cash dividends declared		$ (15,602)			(15,602)
Balance at Sep. 30, 2018	$ 688,168	$ 1,714,621	(473,898)	(18)	1,928,873
Balance (in shares) at Sep. 30, 2018	81,239	(29,311)
Balance at Jun. 30, 2018	$ 682,546	$ 1,636,768	(458,645)	(17)	1,860,652
Balance (in shares) at Jun. 30, 2018	81,105	(29,059)
Increase (Decrease) in Stockholders' Equity
Net income		$ 83,046			83,046
Net unrealized depreciation on marketable securities, net of taxes				(1)	(1)
Exercise of common stock options and stock issued under equity award plan	$ 1,338				1,338
Exercise of common stock options and stock issued under equity award plan (in shares)	103
Sale of common stock under employee stock purchase plan	$ 1,553				1,553
Sale of common stock under employee stock purchase plan (in shares)	31
Stock-based compensation expense associated with equity awards, net of forfeitures	$ 2,731				2,731
Treasury shares acquired from vested employee stock awards for income tax withholdings			(15,161)		(15,161)
Treasury shares acquired from vested employee stock awards for income tax withholdings (in shares)		(250)
Treasury stock purchases			(92)		(92)
Treasury stock purchases (in shares)		(2)
Cash dividends declared		$ (5,193)			(5,193)
Balance at Sep. 30, 2018	$ 688,168	$ 1,714,621	(473,898)	(18)	1,928,873
Balance (in shares) at Sep. 30, 2018	81,239	(29,311)
Increase (Decrease) in Stockholders' Equity
Change in accounting principle and other (see Note 6)		$ (13,141)			(13,141)
Balance at December 31, 2018, as adjusted	$ 690,910	1,763,444	(503,182)	(32)	1,951,140
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
Net income		267,572			267,572
Net unrealized depreciation on marketable securities, net of taxes				$ 32	32
Exercise of common stock options and stock issued under equity award plan	$ 3,105				3,105
Exercise of common stock options and stock issued under equity award plan (in shares)	707
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 associated with equity awards, net of forfeitures	$ 3,506				3,506
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)
Treasury stock purchases			$ (68,477)		(68,477)
Treasury stock purchases (in shares)			(1,229)
Common stock purchased and cancelled	$ (16,145)				(16,145)
Common stock purchased and cancelled (in shares)	(268)
Cash dividends declared		(18,325)			(18,325)
Balance at Sep. 30, 2019	$ 684,541	2,012,691	$ (580,972)		2,116,260
Balance (in shares) at Sep. 30, 2019	81,743		(31,253)
Balance at Jun. 30, 2019	$ 680,802	1,927,412	$ (555,969)		2,052,245
Balance (in shares) at Jun. 30, 2019	81,703		(30,811)
Increase (Decrease) in Stockholders' Equity
Net income		91,339			91,339
Exercise of common stock options and stock issued under equity award plan	$ 185				185
Exercise of common stock options and stock issued under equity award plan (in shares)	13
Sale of common stock under employee stock purchase plan	$ 1,545				1,545
Sale of common stock under employee stock purchase plan (in shares)	27
Stock-based compensation expense associated with equity awards, net of forfeitures	$ 2,009				2,009
Treasury shares acquired from vested employee stock awards for income tax withholdings			$ (25,003)		(25,003)
Treasury stock purchases (in shares)			(442)
Cash dividends declared		(6,060)			(6,060)
Balance at Sep. 30, 2019	$ 684,541	$ 2,012,691	$ (580,972)		$ 2,116,260
Balance (in shares) at Sep. 30, 2019	81,743		(31,253)

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
Net unrealized appreciation on marketable securities, tax			$ 10	$ 11
Cash dividends declared (in dollars per share)	$ 0.12	$ 0.10	$ 0.12	$ 0.10

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
CONSOLIDATED STATEMENTS OF CASH FLOWS
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 582,468	$ 573,127
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(1,469,091)	(1,575,991)
Sales of marketable securities	1,566,471	1,699,284
Proceeds from the sale of aircraft, property and equipment	25,604
Acquisition of property and equipment:
Aircraft and rotable spare parts	(419,508)	(848,723)
Buildings and ground equipment	(61,021)	(35,870)
Deposits on aircraft	(31,817)
Aircraft deposits applied towards acquired aircraft	23,298	21,421
Net cash received from sale of ExpressJet subsidiary	53,200
Decrease (increase) in other assets	7,570	(2,479)
NET CASH USED IN INVESTING ACTIVITIES	(305,294)	(742,358)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of long-term debt	99,914	626,163
Principal payments on long-term debt	(291,250)	(262,923)
Net proceeds from issuance of common stock	6,270	5,212
Purchase of treasury and common stock and employee income tax paid on equity awards	(93,935)	(38,720)
Increase in debt issuance cost	(1,242)	(3,182)
Payment of cash dividends	(17,406)	(14,550)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(297,649)	312,000
Increase (decrease) in cash and cash equivalents	(20,475)	142,769
Cash and cash equivalents at beginning of period	328,384	181,792
CASH AND CASH EQUIVALENTS AT END OF PERIOD	307,909	324,561
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Acquisition of rotable spare parts	3,662	10,346
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	100,100	85,611
Income taxes	2,415	$ 2,382
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

Condensed Consolidated Financia

Condensed Consolidated Financial Statements	9 Months Ended
	Sep. 30, 2019
Condensed Consolidated Financial Statements
Condensed Consolidated Financial Statements	Note 1 — Condensed Consolidated Financial Statements ​ Basis of Presentation ​ The condensed consolidated financial statements of SkyWest, Inc. (“SkyWest” or the “Company”) and its operating subsidiary SkyWest Airlines, Inc. (“SkyWest Airlines”) and its leasing subsidiary SkyWest Leasing, Inc. (“SkyWest Leasing”) included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). On January 22, 2019, the Company completed the sale of its former wholly owned subsidiary, ExpressJet Airlines, Inc. (“ExpressJet”). The Company’s financial and operating results presented in this Report include the financial results of ExpressJet for the period of time ExpressJet was operating as a subsidiary of the Company. Certain information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations, although the Company believes that the following disclosures are adequate to make the information presented not misleading. These condensed consolidated financial statements reflect all adjustments that, in the opinion of management, are necessary to present fairly the results of operations for the interim periods presented. All adjustments are of a normal recurring nature, unless otherwise disclosed. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018. The results of operations for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. ​ The preparation of financial statements in conformity with GAAP 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 will likely differ, and may differ materially, from those estimates and assumptions. ​ Recent Accounting Pronouncements ​ Standards Effective in Future Years and Not Yet Adopted In June 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“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. Early adoption is permitted as of January 1, 2019. The Company anticipates adopting Topic 326 beginning January 1, 2020 and is currently evaluating the impact of this update on the consolidated financial statements. ​ 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. ​ 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 the three and nine months ended September 30, 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, Commitments and Contingencies," for more information. ​

Flying Agreements Revenue and A

Flying Agreements Revenue and Airport Customer Service and Other Revenues	9 Months Ended
	Sep. 30, 2019
Flying Agreements Revenue and Airport Customer Service and Other Revenues
Flying Agreements Revenue and Airport Customer Service and Other Revenues	Note 2 — Flying Agreements Revenue 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 reimburses the Company for certain direct expenses incurred under the fixed-fee arrangement, such as airport landing fees and airport rents. Under the fixed-fee arrangements, the Company’s performance obligation is met 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 nine months ended September 30, 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 nine months ended September 30, 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 $5.3 billion of property and equipment, net as of September 30, 2019, $76.7 million of regional jet aircraft and spare engines was leased to third parties under operating leases as of September 30, 2019. 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. 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 summarizes future minimum rental income under operating leases primarily related to leased aircraft that had remaining non-cancelable lease terms as of September 30, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ October 2019 through December 2019 $ 4,975 2020 ​ 17,733 ​ 2021 ​ 17,333 ​ 2022 ​ 10,775 ​ 2023 ​ 4,549 ​ Thereafter ​ 14,521 ​ ​ ​ $ 69,886 ​ ​ 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 three-and nine-month periods ended September 30, 2019 and 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ 2019 2018 2019 2018 ​ Capacity purchase agreements revenue: flight operations $ 385,537 $ 472,952 $ 1,155,814 $ 1,404,801 ​ Capacity purchase agreements revenue: aircraft lease revenue ​ ​ 207,467 ​ ​ 208,813 ​ ​ 621,526 ​ ​ 599,188 ​ Prorate agreements revenue ​ 145,834 ​ 134,292 ​ 386,833 ​ 373,670 ​ Flying agreements revenue $ 738,838 $ 816,057 $ 2,164,173 $ 2,377,659 ​ 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 ASU No. 2014-09, “Revenue from Contracts with Customers, (Topic 606)” (“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 or quarterly 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 table summarizes the significant provisions of each code-share agreement SkyWest Airlines has with each major airline partner: ​ Delta Connection Agreements Agreement Aircraft type Number of Term / Termination Delta Connection Agreement (fixed-fee arrangement) ​ • CRJ 200 • CRJ 700 • CRJ 900 • E175 ​ 55 14 43 54 ​ • Individual aircraft have scheduled removal dates from 2019 to 2029 Delta Connection Prorate Agreement (revenue-sharing arrangement) ​ • CRJ 200 ​ 28 ​ • Terminable with 30-day notice ​ United Express Agreements Agreement Aircraft type Number of Term / Termination United Express Agreements (fixed-fee arrangement) ​ • CRJ 200 • CRJ 700 • E175 ​ 67 19 65 ​ • Individual aircraft have scheduled removal dates from 2020 to 2029 United Express Prorate Agreement (revenue-sharing arrangement) ​ • CRJ 200 ​ 33 ​ • Terminable with 120-day notice ​ ​ ​ ​ ​ ​ ​ ​ American Agreements Agreement Aircraft type Number of Term / Termination American Agreement (fixed-fee arrangement) ​ • CRJ 700 ​ 66 ​ • Individual aircraft have scheduled removal dates from 2022 to 2025 American Prorate Agreement (revenue-sharing arrangement) ​ • CRJ 200 ​ 7 ​ • Terminable with 120-day notice ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Alaska Capacity Purchase Agreement Agreement Aircraft type Number of Term / Termination Alaska Agreement (fixed-fee arrangement) ​ • E175 ​ 32 ​ • Individual aircraft have scheduled removal dates from 2027 to 2030 ​ In addition to the contractual arrangements described above, SkyWest Airlines has entered into a fixed-fee agreement with Delta to place additional Embraer E175 dual-class regional jet aircraft (“E175”) into service. As of September 30, 2019, the Company was scheduled to take delivery of ​ SkyWest Airlines also entered into an agreement with Delta to operate 13 CRJ900 aircraft under a fixed-fee agreement. As of September 30, 2019, SkyWest Airlines had placed 12 of these CRJ900 aircraft into service with Delta. The delivery date for the remaining aircraft is expected to take place during 2020. The remaining new CRJ900 aircraft will replace a CRJ700 scheduled to expire under SkyWest Airlines’ flying contract with Delta. ​ SkyWest Airlines also entered into an agreement with American to place ten used CRJ700s under a multi-year contract beginning in late 2019. The Company anticipates acquiring seven CRJ700 aircraft from a third party and internally sourcing three CRJ700 aircraft through upcoming scheduled contract expirations. ​ 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. ​ 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, 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.

Share-Based Compensation and St

Share-Based Compensation and Stock Repurchases	9 Months Ended
	Sep. 30, 2019
Share-Based Compensation and Stock Repurchases
Share-Based Compensation and Stock Repurchases	Note 3 — Share-Based Compensation and Stock Repurchases ​ During the nine months ended September 30, 2019, the Company granted 104,120 restricted stock units and 87,864 performance shares to certain employees of the Company and its subsidiaries under the SkyWest, Inc. 2010 Long-Term Incentive Plan and the SkyWest, Inc. 2019 Long-Term Incentive Plan. Both the restricted stock units and performance shares have a per share. During the nine months ended September 30, 2019, the Company did not grant any options to purchase shares of common stock. Additionally, during the nine months ended September 30, 2019, the Company granted The Company accounts for forfeitures of stock options, restricted stock units and performance share grants when forfeitures occur. The estimated fair value of the stock options, restricted stock units and performance shares is amortized over the applicable vesting periods. During the nine months ended September 30, 2019 and 2018, the Company recorded pre-tax share-based compensation expense of million, respectively. Additionally, the Company incurred During the nine months ended September 30, 2019, the Company repurchased 1,496,648 shares of its common stock for $84.6 million and paid $9.3 million for the income tax obligation on vested employee equity awards and issued the net, after-tax shares to employees. During the nine months ended September 30, 2018, the Company repurchased 427,869 shares of its common stock for $25.2 million and paid $13.6 million for the income tax obligation on vested employee equity awards and issued the net, after-tax shares to employees. ​

Net Income Per Common Share

Net Income Per Common Share	9 Months Ended
	Sep. 30, 2019
Net Income Per Common Share
Net Income Per Common Share	Note 4 — 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 per common share. During the nine months ended September 30, 2019, 150,000 performance shares (at target performance) were excluded from the computation of Diluted EPS since the Company had not achieved the minimum target thresholds as of September 30, 2019. During the nine months ended September 30, 2018, 207,000 performance shares (at target performance) were excluded from the computation of Diluted EPS since the Company had not achieved the minimum target thresholds as of September 30, 2018. ​ The calculation of the weighted average number of shares of common stock outstanding for Basic EPS and Diluted EPS for the periods indicated (in thousands, except per share data) is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ 2019 2018 ​ 2019 2018 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net Income ​ $ 91,339 ​ $ 83,046 ​ $ 267,572 ​ $ 213,266 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of common shares outstanding ​ 50,746 ​ 52,039 ​ 51,111 ​ 52,002 ​ ​ Effect of outstanding share-based awards ​ 383 ​ 942 ​ 457 ​ 974 ​ ​ Weighted average number of shares for diluted net income per common share ​ 51,129 ​ 52,981 ​ 51,568 ​ 52,976 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share ​ $ 1.80 ​ $ 1.60 ​ $ 5.24 ​ $ 4.10 ​ ​ Diluted earnings per share ​ $ 1.79 ​ $ 1.57 ​ $ 5.19 ​ $ 4.03 ​ ​ ​

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2019
Segment Reporting
Segment Reporting	Note 5 - Segment Reporting ​ 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 three-month periods ended September 30, 2019 and 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, 2019 ​ ​ ​ SkyWest ​ ​ ​ SkyWest ​ ​ ​ Airlines ExpressJet Leasing Consolidated Operating revenues (1) ​ $ 641,947 ​ $ — ​ $ 118,348 ​ $ 760,295 ​ Operating expense ​ 560,646 ​ — ​ 53,208 ​ 613,854 ​ Depreciation and amortization expense ​ 43,353 ​ — ​ 49,442 ​ 92,795 ​ Interest expense ​ 3,165 ​ — ​ 28,441 ​ 31,606 ​ Segment profit (loss) (2) ​ 78,136 ​ — ​ 36,699 ​ 114,835 ​ Total assets (as of September 30, 2019) ​ 2,744,191 ​ ​ — ​ ​ 3,853,468 ​ 6,597,659 ​ Capital expenditures (including non-cash) ​ 67,394 ​ ​ — ​ ​ 34,597 ​ 101,991 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, 2018 ​ ​ SkyWest ​ ​ ​ SkyWest ​ ​ ​ Airlines ExpressJet Leasing Consolidated Operating revenues (1) ​ $ 607,052 ​ $ 140,155 ​ $ 82,068 ​ $ 829,275 ​ Operating expense ​ 512,278 ​ 139,736 ​ 39,336 ​ 691,350 ​ Depreciation and amortization expense ​ 39,651 ​ 8,683 ​ 37,754 ​ 86,088 ​ Interest expense ​ 4,044 ​ 649 ​ 26,747 ​ 31,440 ​ Segment profit (loss) (2) ​ 90,730 ​ (230) ​ 15,985 ​ 106,485 ​ Identifiable intangible assets, other than goodwill ​ — ​ 1,224 ​ — ​ 1,224 ​ Total assets (as of September 30, 2018) ​ 2,251,563 ​ 565,266 ​ 3,368,031 ​ 6,184,860 ​ Capital expenditures (including non-cash) ​ 44,689 ​ 3,069 ​ 273,808 ​ 321,566 ​ ​ (1) Prorate revenue and airport customer service revenue are primarily reflected in the SkyWest Airlines segment. (2) Segment profit (loss) is equal to operating income less interest expense. ​ The following represents the Company’s segment data for the nine-month periods ended September 30, 2019 and 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2019 ​ ​ ​ SkyWest ​ ​ ​ SkyWest ​ ​ ​ Airlines ExpressJet Leasing Consolidated Operating revenues (1) ​ $ 1,854,803 ​ $ 24,050 ​ $ 349,519 ​ $ 2,228,372 ​ Operating expense ​ 1,651,966 ​ 28,690 ​ 160,763 ​ 1,841,419 ​ Depreciation and amortization expense ​ 124,048 ​ 971 ​ 147,910 ​ 272,929 ​ Special Items ​ ​ 18,508 ​ ​ 3,361 ​ ​ — ​ ​ 21,869 ​ Interest expense ​ 10,699 ​ — ​ 86,185 ​ 96,884 ​ Segment profit (loss) (2) ​ 192,138 ​ (4,640) ​ 102,571 ​ 290,069 ​ Total assets (as of September 30, 2019) ​ 2,744,191 ​ — ​ 3,853,468 ​ 6,597,659 ​ Capital expenditures (including non-cash) ​ 184,019 ​ — ​ 468,213 ​ 652,232 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2018 ​ ​ ​ SkyWest ​ ​ ​ SkyWest ​ ​ ​ Airlines ExpressJet Leasing Consolidated Operating revenues (1) ​ $ 1,750,827 ​ $ 444,943 ​ $ 222,420 ​ $ 2,418,190 ​ Operating expense ​ 1,505,298 ​ 455,084 ​ 105,030 ​ 2,065,412 ​ Depreciation and amortization expense ​ 115,979 ​ 30,044 ​ 100,363 ​ 246,386 ​ Interest expense ​ 12,722 ​ 2,264 ​ 71,499 ​ 86,485 ​ Segment profit (loss) (2) ​ 232,807 ​ (12,405) ​ 45,891 ​ 266,293 ​ Identifiable intangible assets, other than goodwill ​ — ​ 1,224 ​ — ​ 1,224 ​ Total assets (as of September 30, 2018) ​ 2,251,563 ​ 565,266 ​ 3,368,031 ​ 6,184,860 ​ Capital expenditures (including non-cash) ​ 121,010 ​ 5,996 ​ 827,065 ​ 954,071 ​ (1) Prorate revenue and airport customer service revenue are primarily reflected in the SkyWest Airlines segment. (2) Segment profit (loss) is equal to operating income less interest expense. ​

Leases, Commitments and Conting

Leases, Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Leases, Commitments and Contingencies
Leases, Commitments and Contingencies	Note 6 — Leases, Commitments and Contingencies ​ 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 50-seat Bombardier CRJ200 regional jet aircraft (“CRJ200”) . 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 September 30, 2019, the Company’s right-of-use assets were $326.7 million, the Company’s current maturities of operating lease liabilities were $87.5 million, and the Company’s noncurrent lease liabilities were $254.3 million. During the nine months ended September 30, 2019, the Company paid $58.6 million in operating leases reflected as a reduction from operating cash flows. ​ The table below presents lease related terms and discount rates as of September 30, 2019. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2019 Weighted-average remaining lease term ​ Operating leases ​ ​ 6.75 years ​ Weighted-average discount rate ​ ​ ​ Operating leases ​ ​ 6.4% ​ ​ ​ The Company’s lease costs for the three- and nine-months ended September 30, 2019 and 2018 included the following components (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ 2019 2018 Operating lease cost $ 25,173 $ 42,286 Variable and short-term lease cost ​ 1,343 ​ 1,184 Sublease income ​ ​ (357) ​ ​ — Total lease cost $ 26,159 $ 43,470 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ 2019 2018 Operating lease cost $ 80,041 $ 140,544 Variable and short-term lease cost ​ 4,164 ​ 3,996 Sublease income ​ ​ (357) ​ ​ — Total lease cost $ 83,848 $ 144,540 ​ ​ As of September 30, 2019, the Company leased aircraft, airport facilities, office space, and other 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 September 30, 2019 (in thousands): ​ ​ ​ ​ ​ ​ October 2019 through December 2019 $ 17,603 2020 ​ 91,892 ​ 2021 ​ 80,540 ​ 2022 ​ 70,900 ​ 2023 ​ 65,521 ​ Thereafter ​ 103,819 ​ ​ ​ $ 430,275 ​ ​ As of September 30, 2019, the Company had a firm purchase commitment for eleven E175 aircraft from Embraer, S.A. (“Embraer”) with scheduled delivery dates through 2020. The Company has also agreed to purchase seven used CRJ700 aircraft from a third party with anticipated delivery dates in 2020. ​ The following table summarizes the Company’s commitments and obligations as noted for each of the next five years and thereafter (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Oct - Dec 2019 2020 2021 2022 2023 Thereafter Operating lease payments for aircraft and facility obligations ​ $ 430,275 ​ $ 17,603 ​ $ 91,892 ​ $ 80,540 ​ $ 70,900 ​ $ 65,521 ​ $ 103,819 Firm aircraft and spare engine commitments ​ 365,794 ​ ​ 167,037 ​ ​ 187,757 ​ ​ 11,000 ​ ​ — ​ ​ — ​ ​ — ​ Interest commitments (1) ​ 582,997 ​ ​ 31,628 ​ ​ 116,550 ​ ​ 101,468 ​ ​ 87,294 ​ ​ 71,252 ​ ​ 174,805 ​ Principal maturities on long-term debt ​ 3,008,588 ​ ​ 91,192 ​ ​ 361,131 ​ ​ 344,937 ​ ​ 358,586 ​ ​ 367,322 ​ ​ 1,485,420 ​ Total commitments and obligations ​ $ 4,387,654 ​ $ 307,460 ​ $ 757,330 ​ $ 537,945 ​ $ 516,780 ​ $ 504,095 ​ $ 1,764,044 ​ ​ (1) At September 30, 2019, the Company had variable rate notes representing only 0.1% of its total long-term debt. ​ Disclosures related to periods prior to the adoption of the New Lease Standard ​ The following table summarizes future minimum rental payments required under operating leases that have non-cancelable lease terms in excess of one year as of December 31, 2018 (in thousands): ​ ​ ​ ​ ​ ​ 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	9 Months Ended
	Sep. 30, 2019
Fair Value Measurements
Fair Value Measurements	Note 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 the fair value of these assets based on the following three levels of inputs: ​ ​ ​ ​ ​ ​ Level 1 ​ — ​ Quoted prices in active markets for identical assets or liabilities. Level 2 ​ — ​ Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Some of the Company’s marketable securities primarily utilize broker quotes in a non-active market for valuation of these securities. Level 3 ​ — ​ Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities, therefore requiring an entity to develop its own assumptions. As of September 30, 2019, and December 31, 2018, 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 September 30, 2019 ​ Total Level 1 Level 2 Level 3 Cash and cash equivalents ​ $ 307,909 ​ $ 307,909 ​ $ — ​ $ — Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bonds and bond funds ​ $ 207,538 ​ $ — ​ $ 207,538 ​ $ — Commercial paper ​ 56,059 ​ — ​ 56,059 ​ — ​ ​ ​ 263,597 ​ — ​ 263,597 ​ — Total assets measured at fair value ​ $ 571,506 ​ $ 307,909 ​ $ 263,597 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements as of December 31, 2018 ​ Total Level 1 Level 2 Level 3 Cash and cash equivalents ​ $ 328,384 ​ $ 328,384 ​ $ — ​ $ — Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bonds and bond funds ​ $ 229,783 ​ $ — ​ $ 229,783 ​ $ — Commercial paper ​ 131,162 ​ — ​ 131,162 ​ — ​ ​ ​ 360,945 ​ — ​ 360,945 ​ — Total assets measured at fair value ​ $ 689,329 ​ $ 328,384 ​ $ 360,945 ​ $ — ​ The Company’s “marketable securities” classified as Level 2 securities primarily utilize broker quotes in a non-active market for valuation of these securities. ​ The Company did not make any significant transfers of securities between Level 1, Level 2 and Level 3 during the nine months ended September 30, 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. ​ As of September 30, 2019, and December 31, 2018, the Company classified $263.6 million and $360.9 million of marketable securities, respectively, as short-term since it had the intent to maintain a liquid portfolio and the ability to redeem the securities within one year. As of September 30, 2019, and December 31, 2018, the cost of the Company’s total cash and cash equivalents and available for sale securities was ​ The fair value of the Company’s long-term debt classified as Level 2 debt was estimated using discounted cash flow analyses, based on the Company’s current estimated incremental borrowing rates for similar types of borrowing arrangements. 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 estimated to be $2.98 billion as of September 30, 2019 and $3.16 billion as of December 31, 2018, as compared to the carrying amount of $3.01 billion as of September 30, 2019 and $3.19 billion as of December 31, 2018. ​

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2019
Long-Term Debt
Long-Term Debt	Note 8 — Long-Term Debt ​ Long-term debt consisted of the following as of September 30, 2019 and December 31, 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2019 ​ December 31, 2018 Current portion of long-term debt $ 366,248 ​ $ 354,072 Current portion of unamortized debt issue cost, net ​ (3,666) ​ ​ (3,866) Current portion of long-term debt, net of debt issue costs $ 362,582 ​ $ 350,206 ​ ​ ​ ​ ​ ​ Long-term debt, net of current maturities $ 2,642,340 ​ $ 2,831,366 Long-term portion of unamortized debt issue cost, net ​ (20,104) ​ ​ (21,598) Long-term debt, net of current maturities and debt issue costs $ 2,622,236 ​ $ 2,809,768 ​ ​ ​ ​ ​ ​ Total long-term debt (including current portion) $ 3,008,588 ​ $ 3,185,438 Total unamortized debt issue cost, net ​ (23,770) ​ ​ (25,464) Total long-term debt, net of debt issue costs $ 2,984,818 ​ $ 3,159,974 ​ During the nine months ended September 30, 2019, the Company took delivery of five E175 aircraft that the Company financed through $99.9 million of long-term debt. The debt associated with the five E175 aircraft has a 12-year term, is due in quarterly installments with fixed annual interest rates ranging from 3.8% to 4.1% and is secured by the E175 aircraft. Additionally, the Company purchased two previously leased aircraft during the first quarter of 2019, for which the Company assumed $14.5 million of long-term debt. The debt associated with the two previously leased aircraft has a term of 18 months with monthly interest only payments with a fixed annual interest rate of 2.0% and is secured by the previously leased aircraft. ​ As of September 30, 2019, and December 31, 2018, the Company had $72.8 million and $78.7 million, respectively, in letters of credit and surety bonds outstanding with various banks and surety institutions.

Gain on Sale of ExpressJet

Gain on Sale of ExpressJet	9 Months Ended
	Sep. 30, 2019
Gain on Sale of ExpressJet
Gain on Sale of ExpressJet	Note 9 — 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 agreed to lease 16 CRJ200 aircraft to ExpressJet for up to a five-year term as part of the transaction. ​

Special Items

Special Items	9 Months Ended
	Sep. 30, 2019
Special Items
Special Items	Note 10 — Special Items ​ During the nine months ended September 30, 2019, 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 ​ Additionally, during the nine months ended September 30, 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. The Company had no special expense items for the three months ended September 30, 2019. ​

Investment in Other Companies

Investment in Other Companies	9 Months Ended
	Sep. 30, 2019
Investment in Other Companies
Investment in Other Companies	Note 11 — Investment in Other Companies ​ During the nine months ended September 30, 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 ​

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Taxes
Income Taxes	Note 12 — Income Taxes ​ The Company’s effective tax rate for the three months ended September 30, 2019 was 23.1%. The Company’s effective tax rate for the three months ended September 30, 2019 varied from the federal statutory rate of 21.0% primarily due to the provision for state income taxes and the impact of non-deductible expenses, partially offset by a $1.5 million discrete tax benefit from the release of a valuation allowance on federal limited net operating losses. ​ The Company’s effective tax rate for the nine months ended September 30, 2019 was 23.2%. The Company’s effective tax rate for the nine months ended September 30, 2019 varied from the federal statutory rate of 21.0% primarily due to the provision for state income taxes and the impact of non-deductible expenses, partially offset by a $3.6 million discrete tax benefit from excess tax deductions generated from employee equity transactions and a $1.5 million discrete tax benefit from the release of a valuation allowance on federal limited net operating losses that occurred during the nine months ended September 30, 2019. ​

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions
Related Party Transactions	Note 13 — 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 previously announced stock repurchase plan. ​

Legal Matters

Legal Matters	9 Months Ended
	Sep. 30, 2019
Legal Matters
Legal Matters	Note 14 — Legal Matters ​ The Company is subject to certain legal actions which it considers routine to its business activities. As of September 30, 2019, the Company’s 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.

Condensed Consolidated Financ_2

Condensed Consolidated Financial Statements (Policies)	9 Months Ended
	Sep. 30, 2019
Condensed Consolidated Financial Statements
Basis of Presentation	Basis of Presentation ​ The condensed consolidated financial statements of SkyWest, Inc. (“SkyWest” or the “Company”) and its operating subsidiary SkyWest Airlines, Inc. (“SkyWest Airlines”) and its leasing subsidiary SkyWest Leasing, Inc. (“SkyWest Leasing”) included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). On January 22, 2019, the Company completed the sale of its former wholly owned subsidiary, ExpressJet Airlines, Inc. (“ExpressJet”). The Company’s financial and operating results presented in this Report include the financial results of ExpressJet for the period of time ExpressJet was operating as a subsidiary of the Company. Certain information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations, although the Company believes that the following disclosures are adequate to make the information presented not misleading. These condensed consolidated financial statements reflect all adjustments that, in the opinion of management, are necessary to present fairly the results of operations for the interim periods presented. All adjustments are of a normal recurring nature, unless otherwise disclosed. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018. The results of operations for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. ​ The preparation of financial statements in conformity with GAAP 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 will likely differ, and may differ materially, from those estimates and assumptions. ​
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 Accounting Standards Update (“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. Early adoption is permitted as of January 1, 2019. The Company anticipates adopting Topic 326 beginning January 1, 2020 and is currently evaluating the impact of this update on the consolidated financial statements. ​ 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. ​ 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 the three and nine months ended September 30, 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, Commitments and Contingencies," for more information.

Flying Agreements Revenue and_2

Flying Agreements Revenue and Airport Customer Service and Other Revenues (Tables)	9 Months Ended
	Sep. 30, 2019
Agreements with other airlines
Schedule of future minimum rental payments for operating leases	​ ​ ​ ​ ​ ​ October 2019 through December 2019 $ 17,603 2020 ​ 91,892 ​ 2021 ​ 80,540 ​ 2022 ​ 70,900 ​ 2023 ​ 65,521 ​ Thereafter ​ 103,819 ​ ​ ​ $ 430,275 ​
Schedule of flying agreements revenue	The following table represents the Company’s flying agreements revenue by type for the three-and nine-month periods ended September 30, 2019 and 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ 2019 2018 2019 2018 ​ Capacity purchase agreements revenue: flight operations $ 385,537 $ 472,952 $ 1,155,814 $ 1,404,801 ​ Capacity purchase agreements revenue: aircraft lease revenue ​ ​ 207,467 ​ ​ 208,813 ​ ​ 621,526 ​ ​ 599,188 ​ Prorate agreements revenue ​ 145,834 ​ 134,292 ​ 386,833 ​ 373,670 ​ Flying agreements revenue $ 738,838 $ 816,057 $ 2,164,173 $ 2,377,659
Schedule of details of agreements with other airlines	The following table summarizes the significant provisions of each code-share agreement SkyWest Airlines has with each major airline partner: ​ Delta Connection Agreements Agreement Aircraft type Number of Term / Termination Delta Connection Agreement (fixed-fee arrangement) ​ • CRJ 200 • CRJ 700 • CRJ 900 • E175 ​ 55 14 43 54 ​ • Individual aircraft have scheduled removal dates from 2019 to 2029 Delta Connection Prorate Agreement (revenue-sharing arrangement) ​ • CRJ 200 ​ 28 ​ • Terminable with 30-day notice ​ United Express Agreements Agreement Aircraft type Number of Term / Termination United Express Agreements (fixed-fee arrangement) ​ • CRJ 200 • CRJ 700 • E175 ​ 67 19 65 ​ • Individual aircraft have scheduled removal dates from 2020 to 2029 United Express Prorate Agreement (revenue-sharing arrangement) ​ • CRJ 200 ​ 33 ​ • Terminable with 120-day notice ​ ​ ​ ​ ​ ​ ​ ​ American Agreements Agreement Aircraft type Number of Term / Termination American Agreement (fixed-fee arrangement) ​ • CRJ 700 ​ 66 ​ • Individual aircraft have scheduled removal dates from 2022 to 2025 American Prorate Agreement (revenue-sharing arrangement) ​ • CRJ 200 ​ 7 ​ • Terminable with 120-day notice ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Alaska Capacity Purchase Agreement Agreement Aircraft type Number of Term / Termination Alaska Agreement (fixed-fee arrangement) ​ • E175 ​ 32 ​ • Individual aircraft have scheduled removal dates from 2027 to 2030
Aircraft
Agreements with other airlines
Schedule of future minimum rental payments for operating leases	rental income under operating leases primarily related to leased aircraft that had remaining non-cancelable lease terms as of September 30, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ October 2019 through December 2019 $ 4,975 2020 ​ 17,733 ​ 2021 ​ 17,333 ​ 2022 ​ 10,775 ​ 2023 ​ 4,549 ​ Thereafter ​ 14,521 ​ ​ ​ $ 69,886 ​

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2019
Net Income Per Common Share
Schedule of net income per common share	The calculation of the weighted average number of shares of common stock outstanding for Basic EPS and Diluted EPS for the periods indicated (in thousands, except per share data) is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ 2019 2018 ​ 2019 2018 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net Income ​ $ 91,339 ​ $ 83,046 ​ $ 267,572 ​ $ 213,266 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of common shares outstanding ​ 50,746 ​ 52,039 ​ 51,111 ​ 52,002 ​ ​ Effect of outstanding share-based awards ​ 383 ​ 942 ​ 457 ​ 974 ​ ​ Weighted average number of shares for diluted net income per common share ​ 51,129 ​ 52,981 ​ 51,568 ​ 52,976 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share ​ $ 1.80 ​ $ 1.60 ​ $ 5.24 ​ $ 4.10 ​ ​ Diluted earnings per share ​ $ 1.79 ​ $ 1.57 ​ $ 5.19 ​ $ 4.03 ​ ​

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting
Schedule of Company's segment data	The following represents the Company’s segment data for the three-month periods ended September 30, 2019 and 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, 2019 ​ ​ ​ SkyWest ​ ​ ​ SkyWest ​ ​ ​ Airlines ExpressJet Leasing Consolidated Operating revenues (1) ​ $ 641,947 ​ $ — ​ $ 118,348 ​ $ 760,295 ​ Operating expense ​ 560,646 ​ — ​ 53,208 ​ 613,854 ​ Depreciation and amortization expense ​ 43,353 ​ — ​ 49,442 ​ 92,795 ​ Interest expense ​ 3,165 ​ — ​ 28,441 ​ 31,606 ​ Segment profit (loss) (2) ​ 78,136 ​ — ​ 36,699 ​ 114,835 ​ Total assets (as of September 30, 2019) ​ 2,744,191 ​ ​ — ​ ​ 3,853,468 ​ 6,597,659 ​ Capital expenditures (including non-cash) ​ 67,394 ​ ​ — ​ ​ 34,597 ​ 101,991 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, 2018 ​ ​ SkyWest ​ ​ ​ SkyWest ​ ​ ​ Airlines ExpressJet Leasing Consolidated Operating revenues (1) ​ $ 607,052 ​ $ 140,155 ​ $ 82,068 ​ $ 829,275 ​ Operating expense ​ 512,278 ​ 139,736 ​ 39,336 ​ 691,350 ​ Depreciation and amortization expense ​ 39,651 ​ 8,683 ​ 37,754 ​ 86,088 ​ Interest expense ​ 4,044 ​ 649 ​ 26,747 ​ 31,440 ​ Segment profit (loss) (2) ​ 90,730 ​ (230) ​ 15,985 ​ 106,485 ​ Identifiable intangible assets, other than goodwill ​ — ​ 1,224 ​ — ​ 1,224 ​ Total assets (as of September 30, 2018) ​ 2,251,563 ​ 565,266 ​ 3,368,031 ​ 6,184,860 ​ Capital expenditures (including non-cash) ​ 44,689 ​ 3,069 ​ 273,808 ​ 321,566 ​ ​ (1) Prorate revenue and airport customer service revenue are primarily reflected in the SkyWest Airlines segment. (2) Segment profit (loss) is equal to operating income less interest expense. ​ The following represents the Company’s segment data for the nine-month periods ended September 30, 2019 and 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2019 ​ ​ ​ SkyWest ​ ​ ​ SkyWest ​ ​ ​ Airlines ExpressJet Leasing Consolidated Operating revenues (1) ​ $ 1,854,803 ​ $ 24,050 ​ $ 349,519 ​ $ 2,228,372 ​ Operating expense ​ 1,651,966 ​ 28,690 ​ 160,763 ​ 1,841,419 ​ Depreciation and amortization expense ​ 124,048 ​ 971 ​ 147,910 ​ 272,929 ​ Special Items ​ ​ 18,508 ​ ​ 3,361 ​ ​ — ​ ​ 21,869 ​ Interest expense ​ 10,699 ​ — ​ 86,185 ​ 96,884 ​ Segment profit (loss) (2) ​ 192,138 ​ (4,640) ​ 102,571 ​ 290,069 ​ Total assets (as of September 30, 2019) ​ 2,744,191 ​ — ​ 3,853,468 ​ 6,597,659 ​ Capital expenditures (including non-cash) ​ 184,019 ​ — ​ 468,213 ​ 652,232 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2018 ​ ​ ​ SkyWest ​ ​ ​ SkyWest ​ ​ ​ Airlines ExpressJet Leasing Consolidated Operating revenues (1) ​ $ 1,750,827 ​ $ 444,943 ​ $ 222,420 ​ $ 2,418,190 ​ Operating expense ​ 1,505,298 ​ 455,084 ​ 105,030 ​ 2,065,412 ​ Depreciation and amortization expense ​ 115,979 ​ 30,044 ​ 100,363 ​ 246,386 ​ Interest expense ​ 12,722 ​ 2,264 ​ 71,499 ​ 86,485 ​ Segment profit (loss) (2) ​ 232,807 ​ (12,405) ​ 45,891 ​ 266,293 ​ Identifiable intangible assets, other than goodwill ​ — ​ 1,224 ​ — ​ 1,224 ​ Total assets (as of September 30, 2018) ​ 2,251,563 ​ 565,266 ​ 3,368,031 ​ 6,184,860 ​ Capital expenditures (including non-cash) ​ 121,010 ​ 5,996 ​ 827,065 ​ 954,071 ​ (1) Prorate revenue and airport customer service revenue are primarily reflected in the SkyWest Airlines segment. (2) Segment profit (loss) is equal to operating income less interest expense. ​

Leases, Commitments and Conti_2

Leases, Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2019
Summary of related terms and discount rates	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2019 Weighted-average remaining lease term ​ Operating leases ​ ​ 6.75 years ​ Weighted-average discount rate ​ ​ ​ Operating leases ​ ​ 6.4% ​
Summary of lease costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ 2019 2018 Operating lease cost $ 25,173 $ 42,286 Variable and short-term lease cost ​ 1,343 ​ 1,184 Sublease income ​ ​ (357) ​ ​ — Total lease cost $ 26,159 $ 43,470 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ 2019 2018 Operating lease cost $ 80,041 $ 140,544 Variable and short-term lease cost ​ 4,164 ​ 3,996 Sublease income ​ ​ (357) ​ ​ — Total lease cost $ 83,848 $ 144,540 ​ ​
Schedule of future minimum rental payments for operating leases	​ ​ ​ ​ ​ ​ October 2019 through December 2019 $ 17,603 2020 ​ 91,892 ​ 2021 ​ 80,540 ​ 2022 ​ 70,900 ​ 2023 ​ 65,521 ​ Thereafter ​ 103,819 ​ ​ ​ $ 430,275 ​
Summary of commitments and obligations	The following table summarizes the Company’s commitments and obligations as noted for each of the next five years and thereafter (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Oct - Dec 2019 2020 2021 2022 2023 Thereafter Operating lease payments for aircraft and facility obligations ​ $ 430,275 ​ $ 17,603 ​ $ 91,892 ​ $ 80,540 ​ $ 70,900 ​ $ 65,521 ​ $ 103,819 Firm aircraft and spare engine commitments ​ 365,794 ​ ​ 167,037 ​ ​ 187,757 ​ ​ 11,000 ​ ​ — ​ ​ — ​ ​ — ​ Interest commitments (1) ​ 582,997 ​ ​ 31,628 ​ ​ 116,550 ​ ​ 101,468 ​ ​ 87,294 ​ ​ 71,252 ​ ​ 174,805 ​ Principal maturities on long-term debt ​ 3,008,588 ​ ​ 91,192 ​ ​ 361,131 ​ ​ 344,937 ​ ​ 358,586 ​ ​ 367,322 ​ ​ 1,485,420 ​ Total commitments and obligations ​ $ 4,387,654 ​ $ 307,460 ​ $ 757,330 ​ $ 537,945 ​ $ 516,780 ​ $ 504,095 ​ $ 1,764,044 ​ ​ (1) At September 30, 2019, the Company had variable rate notes representing only 0.1% of its total long-term debt.
Previously reported
Schedule of future minimum rental payments for operating leases	The following table summarizes future minimum rental payments required under operating leases that have non-cancelable lease terms in excess of one year as of December 31, 2018 (in thousands): ​ ​ ​ ​ ​ ​ 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)	9 Months Ended
	Sep. 30, 2019
Fair Value Measurements
Schedule of assets measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements as of September 30, 2019 ​ Total Level 1 Level 2 Level 3 Cash and cash equivalents ​ $ 307,909 ​ $ 307,909 ​ $ — ​ $ — Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bonds and bond funds ​ $ 207,538 ​ $ — ​ $ 207,538 ​ $ — Commercial paper ​ 56,059 ​ — ​ 56,059 ​ — ​ ​ ​ 263,597 ​ — ​ 263,597 ​ — Total assets measured at fair value ​ $ 571,506 ​ $ 307,909 ​ $ 263,597 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements as of December 31, 2018 ​ Total Level 1 Level 2 Level 3 Cash and cash equivalents ​ $ 328,384 ​ $ 328,384 ​ $ — ​ $ — Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bonds and bond funds ​ $ 229,783 ​ $ — ​ $ 229,783 ​ $ — Commercial paper ​ 131,162 ​ — ​ 131,162 ​ — ​ ​ ​ 360,945 ​ — ​ 360,945 ​ — Total assets measured at fair value ​ $ 689,329 ​ $ 328,384 ​ $ 360,945 ​ $ — ​

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Long-Term Debt
Schedule of long-term debt	Long-term debt consisted of the following as of September 30, 2019 and December 31, 2018 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2019 ​ December 31, 2018 Current portion of long-term debt $ 366,248 ​ $ 354,072 Current portion of unamortized debt issue cost, net ​ (3,666) ​ ​ (3,866) Current portion of long-term debt, net of debt issue costs $ 362,582 ​ $ 350,206 ​ ​ ​ ​ ​ ​ Long-term debt, net of current maturities $ 2,642,340 ​ $ 2,831,366 Long-term portion of unamortized debt issue cost, net ​ (20,104) ​ ​ (21,598) Long-term debt, net of current maturities and debt issue costs $ 2,622,236 ​ $ 2,809,768 ​ ​ ​ ​ ​ ​ Total long-term debt (including current portion) $ 3,008,588 ​ $ 3,185,438 Total unamortized debt issue cost, net ​ (23,770) ​ ​ (25,464) Total long-term debt, net of debt issue costs $ 2,984,818 ​ $ 3,159,974

Flying Agreements and Airport C

Flying Agreements and Airport Customer Service and Other Revenues (Details) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)aircraft	Sep. 30, 2018USD ($)	Dec. 31, 2019aircraft	Sep. 30, 2019USD ($)aircraft	Sep. 30, 2018USD ($)	Dec. 31, 2016item	Dec. 31, 2018USD ($)
Agreements with other airlines
Percentage of ASMs flown under fixed-fee arrangements				82.10%
Percentage of ASMs flown under pro-rate arrangements				17.90%
Revenues [Abstract]
Operating revenues | $	$ 760,295	$ 829,275		$ 2,228,372	$ 2,418,190
future minimum rental income
October 2019 through December 2019 | $	4,975			4,975
2020 | $	17,733			17,733
2021 | $	17,333			17,333
2022 | $	10,775			10,775
2023 | $	4,549			4,549
Thereafter | $	14,521			14,521
Total | $	69,886			69,886
Property and equipment and related assets | $	5,296,698			$ 5,296,698			$ 5,005,744
Sky West Airlines Inc | Delta Connection Prorate Agreement
future minimum rental income
Number of aircraft				28
Term of agreement				30 days
Sky West Airlines Inc | United Express Prorate Agreement
future minimum rental income
Number of aircraft				33
Term of agreement				120 days
Sky West Airlines Inc | American Prorate Agreement
future minimum rental income
Term of agreement				120 days
Third Party Lease
future minimum rental income
Property and equipment and related assets | $	$ 76,700			$ 76,700
CRJ 200
future minimum rental income
Number of seats on aircraft | item						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 | United Express Agreements
future minimum rental income
Number of aircraft				67
CRJ 700 | American Capacity Purchase Agreement
future minimum rental income
Number of aircraft				66
CRJ 700 | Sky West Airlines Inc | Delta Connection Agreement
future minimum rental income
Number of aircraft				14
CRJ 700 | Sky West Airlines Inc | United Express Agreements
future minimum rental income
Number of aircraft				19
CRJ 700 | American | Forecast
future minimum rental income
Number of aircraft			10
Number of aircraft - acquired from third party			7
Number of aircraft - internal source			3
CRJ 900 | Sky West Airlines Inc | Delta Connection Agreement
future minimum rental income
Number of aircraft				43
Number of aircrafts to be placed in service	12			12
CRJ 900 | Sky West Airlines Inc | Delta Connection Agreement | Minimum
future minimum rental income
Number of aircraft				13
E175 | Sky West Airlines Inc | Delta Connection Agreement
future minimum rental income
Number of aircraft				54
Number of aircraft to be delivered in 2019	5			5
Number of aircraft to be delivered 2020	6			6
Number of additional aircraft placed into service				11
Number of agreed additional aircrafts into service				6
E175 | Sky West Airlines Inc | United Express Agreements
future minimum rental income
Number of aircraft				65
Flying agreements
Revenues [Abstract]
Operating revenues | $	$ 738,838	816,057		$ 2,164,173	2,377,659
Flight operations
Revenues [Abstract]
Operating revenues | $	385,537	472,952		1,155,814	1,404,801
Aircraft lease
Revenues [Abstract]
Operating revenues | $	207,467	208,813		621,526	599,188
Prorate agreements
Revenues [Abstract]
Operating revenues | $	$ 145,834	$ 134,292		$ 386,833	$ 373,670

Share-Based Compensation and _2

Share-Based Compensation and Stock Repurchases (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share-Based Compensation
Upon vesting, each restricted stock unit and performance share replaced with common stock	1.00%
Stock based compensation expense	$ 8	$ 10.4
Employee severance related costs	7.9
Forfeiture credit	$ 4.5
Common stock repurchased (in shares)	1,496,648	427,869
Common stock repurchased, value	$ 84.6	$ 25.2
Payment of income tax obligation on employee equity awards	$ 9.3	$ 13.6
Restricted stock units
Share-Based Compensation
Granted (in dollars per share)	$ 48.73
Restricted stock units | Long Term Incentive Plan 2010
Share-Based Compensation
Granted (in shares)	104,120
Vesting period	3 years
Performance stock units | Long Term Incentive Plan 2010
Share-Based Compensation
Granted (in shares)	87,864
Vesting period	3 years
Performance stock units | Minimum | Long Term Incentive Plan 2010
Share-Based Compensation
Percentage number of performance shares awarded	0.00%
Performance stock units | Maximum | Long Term Incentive Plan 2010
Share-Based Compensation
Percentage number of performance shares awarded	200.00%
Director
Share-Based Compensation
Granted (in shares)	18,576
Granted (in dollars per share)	$ 48.45

Net Income Per Common Share (De

Net Income Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net Income Per Common Share
Number of outstanding units not included in computation of Diluted EPS (in shares)			150,000	207,000
Numerator
Net Income	$ 91,339	$ 83,046	$ 267,572	$ 213,266
Denominator
Weighted average number of common shares outstanding	50,746,000	52,039,000	51,111,000	52,002,000
Effect of outstanding share-based awards	383,000	942,000	457,000	974,000
Weighted average number of shares for diluted net income per common share	51,129,000	52,981,000	51,568,000	52,976,000
Basic earnings per share (in dollars per share)	$ 1.80	$ 1.60	$ 5.24	$ 4.10
Diluted earnings per share (in dollars per share)	$ 1.79	$ 1.57	$ 5.19	$ 4.03

Segment Reporting (Details)

Segment Reporting (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)segment	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Segment Reporting
Number of operating segments | segment			3
Operating revenues	$ 760,295	$ 829,275	$ 2,228,372	$ 2,418,190
Operating expense	613,854	691,350	1,841,419	2,065,412
Depreciation and amortization expense	92,795	86,088	272,929	246,386
Special items			21,869
Interest expense	31,606	31,440	96,884	86,485
Segment profit (loss)	118,738	109,925	348,517	275,455
Identifiable intangible assets, other than goodwill		1,224		1,224
Total assets	6,597,659	6,184,860	6,597,659	6,184,860	$ 6,313,212
Capital expenditures (including non-cash)	101,991	321,566	652,232	954,071
Segments
Segment Reporting
Segment profit (loss)	114,835	106,485	290,069	266,293
SkyWest Airlines
Segment Reporting
Operating revenues	641,947	607,052	1,854,803	1,750,827
Operating expense	560,646	512,278	1,651,966	1,505,298
Depreciation and amortization expense	43,353	39,651	124,048	115,979
Special items			18,508
Interest expense	3,165	4,044	10,699	12,722
Total assets	2,744,191	2,251,563	2,744,191	2,251,563
Capital expenditures (including non-cash)	67,394	44,689	184,019	121,010
SkyWest Airlines | Segments
Segment Reporting
Segment profit (loss)	78,136	90,730	192,138	232,807
ExpressJet Airlines Inc
Segment Reporting
Operating revenues		140,155	24,050	444,943
Operating expense		139,736	28,690	455,084
Depreciation and amortization expense		8,683	971	30,044
Special items			3,361
Interest expense		649		2,264
Identifiable intangible assets, other than goodwill		1,224		1,224
Total assets		565,266		565,266
Capital expenditures (including non-cash)		3,069		5,996
ExpressJet Airlines Inc | Segments
Segment Reporting
Segment profit (loss)		(230)	(4,640)	(12,405)
SkyWest Leasing
Segment Reporting
Operating revenues	118,348	82,068	349,519	222,420
Operating expense	53,208	39,336	160,763	105,030
Depreciation and amortization expense	49,442	37,754	147,910	100,363
Interest expense	28,441	26,747	86,185	71,499
Total assets	3,853,468	3,368,031	3,853,468	3,368,031
Capital expenditures (including non-cash)	34,597	273,808	468,213	827,065
SkyWest Leasing | Segments
Segment Reporting
Segment profit (loss)	$ 36,699	$ 15,985	$ 102,571	$ 45,891

Leases, Commitments and Conti_3

Leases, Commitments and Contingencies - Leases (Details) $ in Thousands	Jan. 01, 2019USD ($)	Sep. 30, 2019USD ($)aircraft	Mar. 31, 2019USD ($)aircraft	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)aircraft	Sep. 30, 2018USD ($)	Dec. 31, 2016item
Lessee, Lease, Description [Line Items]
Number of aircraft leased | aircraft					91
Operating lease right-of-use assets		$ 326,700			$ 326,700
Current maturities of lease liabilities		87,472			87,472
Noncurrent operating leases		$ 254,258			254,258
Operating leases					$ 58,600
Weighted-average remaining lease term: Operating leases		6 years 9 months			6 years 9 months
Weighted-average discount rate: Operating leases		6.40%			6.40%
Lease costs
Operating lease cost		$ 25,173		$ 42,286	$ 80,041	$ 140,544
Variable and short-term lease cost		1,343		1,184	4,164	3,996
Sublease income		(357)			(357)
Total lease cost		$ 26,159		$ 43,470	$ 83,848	$ 144,540
CRJ 200
Lessee, Lease, Description [Line Items]
Number of seats on aircraft | item							50
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, Commitments and Conti_4

Leases, Commitments and Contingencies (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)aircraft
Future minimum rental payments required under operating leases
October 2019 through December 2019	$ 17,603
2020	91,892
2021	80,540
2022	70,900
2023	65,521
Thereafter	103,819
Total	$ 430,275
E175
Future minimum rental payments required under operating leases
Number of aircraft under firm purchase commitment | aircraft	11
CRJ 700
Future minimum rental payments required under operating leases
Number of aircraft under firm purchase commitment | aircraft	7

Leases, Commitments and Conti_5

Leases, Commitments and Contingencies - Commitments and Obligations (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Operating lease payments for aircraft and facility obligations
Oct - Dec 2019	$ 17,603
2020	91,892
2021	80,540
2022	70,900
2023	65,521
Thereafter	103,819
Total	430,275
Firm aircraft and spare engine commitments
Oct - Dec 2019	167,037
2020	187,757
2021	11,000
Total	365,794
Interest commitments
Oct - Dec 2019	31,628
2020	116,550
2021	101,468
2022	87,294
2023	71,252
Thereafter	174,805
Total	582,997
Principal maturities on long-term debt
Oct - Dec 2019	91,192
2020	361,131
2021	344,937
2022	358,586
2023	367,322
Thereafter	1,485,420
Total long-term debt	3,008,588	$ 3,185,438
Total commitments and obligations
Oct - Dec 2019	307,460
2020	757,330
2021	537,945
2022	516,780
2023	504,095
Thereafter	1,764,044
Total	$ 4,387,654
Variable interest rate (as a percent)	0.10%
Previously reported
Operating lease payments for aircraft and facility obligations
Oct - Dec 2019	$ 87,256
2020	101,741
2021	90,787
2022	72,593
2023	65,749
Thereafter	59,820
Total	$ 477,946

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value Measurements
Marketable Securities	$ 263,597	$ 360,945
Fair Value of Financial Instruments
Carrying amount of long-term debt	2,984,818	3,159,974
Recurring
Fair Value Measurements
Cost of cash and cash equivalents and available for sale securities	571,400	689,400
Recurring | Fair value
Fair Value Measurements
Cash and cash equivalents	307,909	328,384
Marketable Securities	263,597	360,945
Total assets measured at fair value	571,506	689,329
Recurring | Fair value | Bonds and bond funds
Fair Value Measurements
Marketable Securities	207,538	229,783
Recurring | Fair value | Commercial paper
Fair Value Measurements
Marketable Securities	56,059	131,162
Recurring | Level 1
Fair Value Measurements
Cash and cash equivalents	307,909	328,384
Total assets measured at fair value	307,909	328,384
Recurring | Level 2
Fair Value Measurements
Marketable Securities	263,597	360,945
Total assets measured at fair value	263,597	360,945
Fair Value of Financial Instruments
Fair value of long-term debt	2,980,000	3,160,000
Carrying amount of long-term debt	3,010,000	3,190,000
Recurring | Level 2 | Bonds and bond funds
Fair Value Measurements
Marketable Securities	207,538	229,783
Recurring | Level 2 | Commercial paper
Fair Value Measurements
Marketable Securities	$ 56,059	$ 131,162

Long-term Debt (Details)

Long-term Debt (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)aircraft	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Current portion long-term debt	$ 366,248	$ 354,072
Less current portion of unamortized debt issue cost, net	(3,666)	(3,866)
Current portion of long-term debt, net of debt issue costs	362,582	350,206
Long-term debt, net of current maturities	2,642,340	2,831,366
Less long-term portion of unamortized debt issue cost, net	(20,104)	(21,598)
Long-term debt, net of current maturities and debt issue costs	2,622,236	2,809,768
Total long-term debt (including current portion)	3,008,588	3,185,438
Total unamortized debt issue cost, net	(23,770)	(25,464)
Total	$ 2,984,818	3,159,974
Number of aircraft leased | aircraft	91
Debt issued to purchase of aircraft	$ 14,500
Letter of credit
Debt Instrument [Line Items]
Amount outstanding	$ 72,800	$ 78,700
E175
Debt Instrument [Line Items]
Number of aircraft delivered | aircraft	5
Purchase of aircraft financed through long-term debt	$ 99,900
Debt instrument, term	12 years
Purchased, previously-leased aircraft
Debt Instrument [Line Items]
Number of aircraft purchased | aircraft	2
Debt instrument, term	18 months
Interest rate (as a percent)	2.00%
Minimum | E175
Debt Instrument [Line Items]
Interest rate (as a percent)	3.80%
Maximum | E175
Debt Instrument [Line Items]
Interest rate (as a percent)	4.10%

Gain on Sale of ExpressJet (Det

Gain on Sale of ExpressJet (Details) $ in Thousands	Jan. 22, 2019USD ($)aircraft	Jan. 11, 2019USD ($)	Sep. 30, 2019USD ($)
Gain on sale	$ 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
Lease term (in years)			5 years

Special Items (Details)

Special Items (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Special Items
Agreement termination non cash expense		$ 18.5
Employee severance cost		$ 3.4
Special expense items	$ 0

Investment in Other Companies (

Investment in Other Companies (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)engine	Dec. 31, 2018USD ($)
Number of spare engines purchased | engine	14
Long-term debt	$ 2,984,818	$ 3,159,974
Aero Engines, LLC.
Payments to Acquire Interest in Joint Venture	$ 22,300
Investment ownership (as a percent)	75.00%
Number of spare engines sold to Aero Engines | engine	14
Long-term debt	$ 0
Investment balance in Aero Engines	22,600
Company's portion of income generated by Aero Engines	$ 300

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Effective tax rate (as a percent)	23.10%	23.20%
Statutory Federal income tax rate (as a percent)	21.00%	21.00%
Accounting Standards Update 2016-09
Discrete tax benefit	$ 1.5	$ 3.6
Capital loss carryforward valuation allowance		$ 1.5

Related Party Transactions (Det

Related Party Transactions (Details) - Jerry Atkin	Jun. 13, 2019$ / sharesshares
Related Party Transactions
Common stock purchased and cancelled (in shares) | shares	268,025
Share price (in dollars per share) | $ / shares	$ 60.24
Period of trading days prior to repurchase to calculate volume-weighted average closing price	5 days