Amkor Technology (AMKR) 10-Q 5 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 28, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	AMKOR TECHNOLOGY, INC.
Entity Central Index Key	1,047,127
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		239,014,726

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Net sales	$ 913,600	$ 868,682
Cost of sales	770,694	745,798
Gross profit	142,906	122,884
Selling, general and administrative	76,695	73,635
Research and development	41,556	27,155
Total operating expenses	118,251	100,790
Operating income	24,655	22,094
Interest expense	21,254	16,192
Interest expense, related party	1,242	1,242
Other (income) expense, net	10,864	3,192
Total other expense, net	33,360	20,626
Income (loss) before taxes	(8,705)	1,468
Income tax expense	439	1,873
Net income (loss)	(9,144)	(405)
Net income attributable to non-controlling interests	(862)	(470)
Net income (loss) attributable to Amkor	$ (10,006)	$ (875)
Net income (loss) attributable to Amkor per common share:
Basic (in dollars per share)	$ (0.04)	$ 0
Diluted (in dollars per share)	$ (0.04)	$ 0
Shares used in computing per common share amounts:
Basic (in shares)	238,685	237,025
Diluted (in shares)	238,685	237,025

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (9,144)	$ (405)
Other comprehensive income (loss), net of tax:
Adjustments to unrealized components of defined benefit pension plans	230	24
Foreign currency translation	13,586	19,323
Total other comprehensive income (loss)	13,816	19,347
Comprehensive income	4,672	18,942
Comprehensive income attributable to non-controlling interests	(862)	(470)
Comprehensive income attributable to Amkor	$ 3,810	$ 18,472

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 613,974	$ 549,518
Restricted cash	2,000	2,000
Accounts receivable, net of allowances	545,794	563,107
Inventories	267,208	267,990
Other current assets	65,689	27,081
Total current assets	1,494,665	1,409,696
Property, plant and equipment, net	2,551,706	2,564,648
Goodwill	25,228	24,122
Restricted cash	4,263	3,977
Other assets	102,459	89,643
Total assets	4,178,321	4,092,086
Current liabilities:
Short-term borrowings and current portion of long-term debt	36,927	35,192
Trade accounts payable	453,686	487,430
Capital expenditures payable	209,831	144,370
Accrued expenses	338,663	338,669
Total current liabilities	1,039,107	1,005,661
Long-term debt	1,450,737	1,364,638
Long-term debt, related party	35,000	75,000
Pension and severance obligations	177,374	166,701
Other non-current liabilities	67,174	76,682
Total liabilities	2,769,392	2,688,682
Commitments and contingencies (Note 16)
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000 shares authorized, designated Series A, none issued	0	0
Common stock, $0.001 par value, 500,000 shares authorized; 284,552 and 284,479 shares issued; and 238,717 and 238,665 shares outstanding, in 2017 and 2016, respectively	285	284
Additional paid-in capital	1,896,286	1,895,089
Accumulated deficit	(313,563)	(303,557)
Accumulated other comprehensive income (loss)	20,078	6,262
Treasury stock, at cost, 45,835 and 45,814 shares, in 2017 and 2016, respectively	(214,700)	(214,490)
Total Amkor stockholders’ equity	1,388,386	1,383,588
Non-controlling interests in subsidiaries	20,543	19,816
Total equity	1,408,929	1,403,404
Total liabilities and equity	$ 4,178,321	$ 4,092,086

Consolidated Balance Sheets (U5

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
Stockholders’ equity:
Preferred stock designated Series A, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock designated Series A, shares authorized	10,000,000	10,000,000
Preferred stock designated Series A, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	284,552,000	284,479,000
Common stock, shares outstanding	238,717,000	238,665,000
Treasury stock, shares	45,835,000	45,814,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ (9,144)	$ (405)
Depreciation and amortization	141,816	137,136
Other operating activities and non-cash items	(7,890)	(3,944)
Changes in assets and liabilities	(22,105)	5,311
Net cash provided by operating activities	102,677	138,098
Cash flows from investing activities:
Payments for property, plant and equipment	(88,285)	(198,788)
Proceeds from sale of property, plant and equipment	1,835	121
Other investing activities	(2,492)	(426)
Net cash used in investing activities	(88,942)	(199,093)
Cash flows from financing activities:
Payments under revolving credit facilities	0	(40,000)
Borrowings under short-term debt	13,275	0
Payments of short-term debt	(14,073)	(11,901)
Proceeds from issuance of long-term debt	50,000	0
Payments of long-term debt	(3,295)	(4,204)
Payments for debt issuance costs	(156)	(156)
Payment of deferred consideration for purchase of facility	(3,890)	0
Payments for capital lease obligations	(913)	(401)
Proceeds from the issuance of stock through share-based compensation plans	145	0
Payments of tax withholding for restricted shares	(210)	(119)
Payments of subsidiary dividends to non-controlling interests	(135)	(135)
Net cash provided by (used in) financing activities	40,748	(56,916)
Effect of exchange rate fluctuations on cash, cash equivalents and restricted cash	10,259	8,250
Net increase (decrease) in cash, cash equivalents and restricted cash	64,742	(109,661)
Cash, cash equivalents and restricted cash, beginning of period	555,495	527,348
Cash, cash equivalents and restricted cash, end of period	620,237	417,687
Non-cash investing and financing activities:
Property, plant and equipment included in capital expenditures payable	$ 211,410	$ 199,944

Interim Financial Statements

Interim Financial Statements	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interim Financial Statements	Interim Financial Statements Basis of Presentation. The Consolidated Financial Statements and related disclosures as of March 31, 2017 , and for the three months ended March 31, 2017 and 2016 , are unaudited, pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). The December 31, 2016 , Consolidated Balance Sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“U.S.”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) have been condensed or omitted pursuant to such rules and regulations. In our opinion, these financial statements include all adjustments (consisting only of normal recurring adjustments) necessary for the fair statement of the results for the interim periods. These financial statements should be read in conjunction with the financial statements included in our Annual Report for the year ended December 31, 2016 , filed on Form 10-K with the SEC on February 24, 2017. The results of operations for the three months ended March 31, 2017 , are not necessarily indicative of the results to be expected for the full year. Unless the context otherwise requires, all references to “Amkor,” “we,” “us,” “our” or the “company” are to Amkor Technology, Inc. and our subsidiaries. Use of Estimates. The Consolidated Financial Statements have been prepared in conformity with U.S. GAAP, using management’s best estimates and judgments where appropriate. These estimates and judgments affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. The estimates and judgments will also affect the reported amounts for certain revenues and expenses during the reporting period. Actual results could differ materially from these estimates and judgments. Goodwill. The balance of goodwill in our Consolidated Balance Sheets reflects adjustments for foreign currency translation.

New Accounting Standards

New Accounting Standards	3 Months Ended
	Mar. 31, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Standards	New Accounting Standards Recently Adopted Standards In July 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2015-11, Inventory - Simplifying the Measurement of Inventory (Topic 330) . ASU 2015-11 requires inventory to be subsequently measured using the lower of cost and net realizable value, thereby eliminating the market value approach. Net realizable value is defined as the “estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation.” ASU 2015-11 is effective for reporting periods beginning after December 15, 2016 and is applied prospectively. We adopted ASU 2015-11 at January 1, 2017. The adoption of ASU 2015-11 did not have a significant impact on our financial statements or disclosure. In January 2017, the FASB issued ASU 2017-04, Intangible - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment . ASU 2017-04 simplifies the goodwill impairment test by eliminating the second step of the current two-step impairment test. ASU 2017-04 is effective for interim and annual goodwill impairment tests in fiscal years beginning after December 15, 2019 and is applied prospectively. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We adopted ASU 2017-04 at January 1, 2017. The adoption of ASU 2017-04 did not have a significant impact on our financial statements or disclosure. Recently Issued Standards In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) . ASU 2014-09 is based on the principle that revenue is recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers, including significant judgments and changes in judgments. ASU 2014-09 permits the use of either full retrospective or modified retrospective methods of adoption. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date , which defers the effective date by one year to December 15, 2017, for interim and annual reporting periods beginning after that date . In March, April, May and December 2016, the FASB issued ASU 2016-08, ASU 2016-10, ASU 2016-12 and ASU 2016-20, respectively, which provide supplemental guidance and clarification to ASU 2014-09. Early adoption is permitted, but we do not plan to adopt this standard early. We are currently evaluating the impact that this guidance will have on our financial statements and disclosure and have not yet selected a transition method. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) . ASU 2016-02 requires a dual approach for lessee accounting under which a lessee would account for leases as finance leases or operating leases. Both finance leases and operating leases will result in the lessee recognizing a right-of-use asset and a corresponding lease liability. For finance leases the lessee would recognize interest expense and amortization of the right-of-use asset, and for operating leases the lessee would recognize a straight-line lease expense. ASU 2016-02 is effective for reporting periods beginning after December 15, 2018 using a modified retrospective approach. Early adoption is permitted. We are currently evaluating the impact that this guidance may have on our financial statements and disclosure. In March 2017, the FASB issued ASU 2017-07, Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost . ASU 2017-07 requires that the service cost component of net periodic pension costs be presented in the same line item as other compensation costs and all other components of net periodic pension costs to be presented in the statement of income as nonoperating expenses. ASU 2017-07 is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods. Early adoption is permitted and should be applied retrospectively. We are currently evaluating the impact that this guidance may have on our financial statements and disclosure.

Acquisition

Acquisition	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Acquisition	Acquisition In February 2017, we entered into a definitive agreement to acquire 100% of the shares of NANIUM, S.A., a provider of wafer-level fan-out semiconductor packaging solutions. The transaction is expected to close in the second quarter of 2017, subject to customary closing conditions and regulatory approvals.

Share-Based Compensation Plans

Share-Based Compensation Plans	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation Plans	Share-Based Compensation Plans The following table summarizes our share-based compensation expense attributable to stock options and restricted shares: For the Three Months Ended 2017 2016 (In thousands) Share-based compensation expense $ 1,053 $ 805 We recognized our share-based compensation costs primarily in selling, general and administrative expenses. There were no corresponding deferred income tax benefits for stock options or restricted shares. Stock Options The following table summarizes our stock option activity for the three months ended March 31, 2017 : Number of Shares (In thousands) Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (In thousands) Outstanding at December 31, 2016 2,443 $ 6.93 Granted 2,735 9.86 Exercised (27 ) 5.49 Forfeited or expired — — Outstanding at March 31, 2017 5,151 $ 8.49 7.96 $ 15,973 Fully vested at March 31, 2017 and expected to vest thereafter 4,962 $ 8.45 7.89 $ 15,580 Exercisable at March 31, 2017 1,671 $ 7.30 4.61 $ 7,190 The following assumptions were used to calculate the weighted-average fair values of the options granted: For the Three Months Ended 2017 2016 Expected life (in years) 5.6 6.0 Risk-free interest rate 1.9 % 1.5 % Volatility 43 % 44 % Dividend yield — — Weighted-average grant date fair value per option granted $ 4.16 $ 2.02 Total unrecognized compensation expense from stock options was $12.1 million as of March 31, 2017 , which is expected to be recognized over a weighted-average period of 3.5 years beginning April 1, 2017 . Restricted Shares The following table summarizes our restricted share activity for the three months ended March 31, 2017 : Number of Shares (In thousands) Weighted- Average Grant Date Fair Value (Per share) Non-vested at December 31, 2016 145 $ 5.02 Awards granted 200 9.86 Awards vested (47 ) 4.50 Awards forfeited — — Non-vested at March 31, 2017 298 $ 8.35 Total unrecognized compensation cost from restricted shares was $1.9 million as of March 31, 2017 , which is expected to be recognized over a weighted-average period of 2.7 years beginning April 1, 2017 .

Other Income and Expense

Other Income and Expense	3 Months Ended
	Mar. 31, 2017
Other Income and Expenses [Abstract]
Other Income and Expense	Other Income and Expense Other income and expense consists of the following: For the Three Months Ended 2017 2016 (In thousands) Interest income $ (511 ) $ (404 ) Foreign currency (gain) loss, net 11,384 3,623 Other (9 ) (27 ) Other (income) expense, net $ 10,864 $ 3,192

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our income tax expense of $0.4 million for the three months ended March 31, 2017 primarily reflects income taxes at certain of our foreign operations and foreign withholding taxes. Our income tax expense also reflects income taxed in foreign jurisdictions where we benefit from tax holidays. We monitor on an ongoing basis our ability to utilize our deferred tax assets and whether there is a need for a related valuation allowance. In evaluating our ability to recover our deferred tax assets in the jurisdictions from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax-planning strategies and results of recent operations. For most of our foreign deferred tax assets, we consider it more likely than not that we will have sufficient taxable income to allow us to realize these deferred tax assets. We maintain a valuation allowance on all our U.S. net deferred tax assets, including our net operating loss carryforwards. Such valuation allowances are released as the related tax benefits are realized or when sufficient evidence exists to conclude that it is more likely than not that the deferred tax assets will be realized. Unrecognized tax benefits represent reserves for potential tax deficiencies or reductions in tax benefits that could result from federal, state or foreign tax audits. Our gross unrecognized tax benefits increased from $23.1 million at December 31, 2016 , to $24.7 million as of March 31, 2017 . Most of our unrecognized tax benefits would reduce our effective tax rate, if recognized. Our unrecognized tax benefits are subject to change for effective settlement of examinations, changes in the recognition threshold of tax positions, the expiration of statues of limitations and other factors. Tax return examinations involve uncertainties, and there can be no assurance that the outcome of examinations will be favorable.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per share (“EPS”) is computed by dividing net income attributable to Amkor common stockholders by the weighted-average number of common shares outstanding during the period. The weighted-average number of common shares outstanding is reduced for treasury stock. Diluted EPS is computed based on the weighted-average number of common shares outstanding plus the effect of dilutive potential common shares outstanding during the period. Dilutive potential common shares include outstanding stock options and unvested restricted shares. The following table summarizes the computation of basic and diluted EPS: For the Three Months Ended 2017 2016 (In thousands, except per share data) Net income (loss) available to Amkor common stockholders $ (10,006 ) $ (875 ) Weighted-average number of common shares outstanding — basic 238,685 237,025 Weighted-average number of common shares outstanding — diluted 238,685 237,025 Net income (loss) attributable to Amkor per common share: Basic $ (0.04 ) $ — Diluted (0.04 ) — The following table summarizes the potential shares of common stock that were excluded from diluted EPS, because the effect of including these potential shares was anti-dilutive: For the Three Months Ended 2017 2016 (In thousands) Stock options and restricted share awards 5,449 4,033

Equity and Accumulated Other Co

Equity and Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Equity and Accumulated Other Comprehensive Income (Loss)	Equity and Accumulated Other Comprehensive Income (Loss) Changes in equity consist of the following: Attributable to Amkor Attributable to Non-controlling Interests Total (In thousands) Equity at December 31, 2016 $ 1,383,588 $ 19,816 $ 1,403,404 Net income (loss) (10,006 ) 862 (9,144 ) Other comprehensive income (loss) 13,816 — 13,816 Issuance of stock through employee share-based compensation plans 145 — 145 Treasury stock acquired through surrender of shares for tax withholding (210 ) — (210 ) Share-based compensation 1,053 — 1,053 Subsidiary dividends paid to non-controlling interests — (135 ) (135 ) Equity at March 31, 2017 $ 1,388,386 $ 20,543 $ 1,408,929 Attributable to Amkor Attributable to Non-controlling Interests Total (In thousands) Equity at December 31, 2015 $ 1,200,286 $ 17,250 $ 1,217,536 Net income (loss) (875 ) 470 (405 ) Other comprehensive income (loss) 19,347 — 19,347 Treasury stock acquired through surrender of shares for tax withholding (119 ) — (119 ) Share-based compensation 805 — 805 Subsidiary dividends paid to non-controlling interests — (135 ) (135 ) Equity at March 31, 2016 $ 1,219,444 $ 17,585 $ 1,237,029 Changes in accumulated other comprehensive income (loss), net of tax, consist of the following: Defined Benefit Pension Foreign Currency Translation Total (In thousands) Accumulated other comprehensive income (loss) at December 31, 2016 $ 1,138 $ 5,124 $ 6,262 Other comprehensive income (loss) before reclassifications — 13,586 13,586 Amounts reclassified from accumulated other comprehensive income (loss) 230 — 230 Other comprehensive income (loss) 230 13,586 13,816 Accumulated other comprehensive income (loss) at March 31, 2017 $ 1,368 $ 18,710 $ 20,078 Defined Benefit Pension Foreign Currency Translation Total (In thousands) Accumulated other comprehensive income (loss) at December 31, 2015 $ (1,425 ) $ (659 ) $ (2,084 ) Other comprehensive income (loss) before reclassifications — 19,323 19,323 Amounts reclassified from accumulated other comprehensive income (loss) 24 — 24 Other comprehensive income (loss) 24 19,323 19,347 Accumulated other comprehensive income (loss) at March 31, 2016 $ (1,401 ) $ 18,664 $ 17,263 Amounts reclassified out of accumulated other comprehensive income (loss) are included as a component of net periodic pension cost ( Note 14 ).

Factoring of Accounts Receivabl

Factoring of Accounts Receivable	3 Months Ended
	Mar. 31, 2017
Factoring of Accounts Receivable [Abstract]
Factoring of Accounts Receivable	Factoring of Accounts Receivable In certain foreign locations, we use non-recourse factoring arrangements with third-party financial institutions to manage our working capital and cash flows. Under this program, we sell receivables to a financial institution for cash at a discount to the face amount. As part of the factoring arrangements, we perform certain collection and administrative functions for the receivables sold. For the three months ended March 31, 2017 and 2016 , we sold accounts receivable totaling $132.2 million and $139.1 million for a discount, plus fees, of $0.8 million and $0.4 million , respectively.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2017
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consist of the following: March 31, December 31, 2016 (In thousands) Raw materials and purchased components $ 179,932 $ 173,035 Work-in-process 87,276 94,955 Total inventories $ 267,208 $ 267,990

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant And Equipment	Property, Plant and Equipment Property, plant and equipment consist of the following: March 31, December 31, 2016 (In thousands) Land $ 215,566 $ 240,719 Land use rights 26,845 26,845 Buildings and improvements 1,339,370 1,362,007 Machinery and equipment 4,580,400 4,483,523 Software and computer equipment 208,655 205,969 Furniture, fixtures and other equipment 22,133 21,313 Construction in progress 89,799 87,037 Total property, plant and equipment 6,482,768 6,427,413 Accumulated depreciation and amortization (3,931,062 ) (3,862,765 ) Total property, plant and equipment, net $ 2,551,706 $ 2,564,648 The following table summarizes our depreciation expense: For the Three Months Ended 2017 2016 (In thousands) Depreciation expense $ 141,456 $ 136,508 We had $46.8 million and $44.8 million of costs for our factory and research and development facility in Korea ("K5") in construction in progress as of March 31, 2017 and December 31, 2016 , respectively. As part of our plan to consolidate factory operations in Korea, we sold the land and buildings comprising our K1 factory in May 2017 for ₩162.1 billion ( $142.4 million ). We received 10% of the sale price at signing in November 2016 and the balance at closing in May 2017. In May 2017, we recognized a pre-tax gain of $108.1 million . As of March 31, 2017, $34.3 million was classified as assets held for sale and recorded in other current assets in our Consolidated Balance Sheet.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2017
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consist of the following: March 31, December 31, (In thousands) Payroll and benefits $ 116,526 $ 117,636 Deferred revenue and customer advances 58,873 65,653 Accrued settlement costs 35,908 35,304 Accrued interest 28,083 13,046 Income taxes payable 25,453 37,961 Accrued severance plan obligations 15,266 14,053 Other accrued expenses 58,554 55,016 Total accrued expenses $ 338,663 $ 338,669

Debt

Debt	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt Following is a summary of short-term borrowings and long-term debt: March 31, December 31, (In thousands) Debt of Amkor Technology, Inc.: Senior secured credit facilities: $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due $ — $ — Senior notes: 6.625% Senior notes, due June 2021 400,000 400,000 6.375% Senior notes, due October 2022 524,971 524,971 Debt of subsidiaries: Amkor Technology Korea, Inc.: $100 million revolving credit facility, foreign currency funding-linked base rate plus 1.60%, due June 2017 (2) — — Term loan, LIBOR plus 2.60%, due May 2018 120,000 120,000 Term loan, LIBOR plus 2.70%, due December 2019 55,000 55,000 Term loan, foreign currency funding-linked base rate plus 1.32%, due May 2020 150,000 150,000 Term loan, foreign currency funding-linked base rate plus 1.33%, due May 2020 (2) 80,000 80,000 Term loan, fund floating rate plus 1.60%, due June 2020 (3) 86,000 86,000 J-Devices Corporation: Short-term term loans, variable rate (4) 22,370 22,230 Term loans, fixed rate at 0.53%, due April 2018 16,964 19,460 Other: Revolving credit facility, TAIFX plus a bank-determined spread, due 20,000 20,000 Term loan, LIBOR plus 1.80%, due December 2019 (China) (6) 50,000 — 1,525,305 1,477,661 Less: Unamortized premium and deferred debt costs, net (2,641 ) (2,831 ) Less: Short-term borrowings and current portion of long-term debt (36,927 ) (35,192 ) Long-term debt (including related party) $ 1,485,737 $ 1,439,638 (1) Our $200.0 million senior secured revolving credit facility has a letter of credit sub-limit facility of $25.0 million . Principal is payable at maturity. The availability for the revolving credit facility is based on the amount of our eligible accounts receivable, which was $166.0 million as of March 31, 2017 . Additionally, we had $ 0.5 million of standby letters of credit outstanding, resulting in $165.5 million available to be drawn as of March 31, 2017 . (2) In June 2012, we entered into a $41.0 million revolving credit facility. In March 2016, we increased the facility to $100.0 million . Principal is payable at maturity. Interest is payable monthly in arrears, at a foreign currency funding-linked base rate plus 1.60% ( 3.62% as of March 31, 2017 ). As of March 31, 2017 , $100.0 million was available to be drawn. In April 2017, we borrowed $75.0 million on this facility and repaid the outstanding balance of $80.0 million on our term loan due May 2020. (3) In May 2015, we entered into a term loan agreement pursuant to which we may borrow up to $150.0 million for capital expenditures. Principal is payable at maturity. Interest is payable quarterly in arrears, at a fund floating rate plus 1.60% ( 2.93% as of March 31, 2017 ). As of March 31, 2017 , $64.0 million was available to be borrowed. (4) We entered into various short-term term loans which mature semiannually. Principal is payable in monthly installments. Interest is payable monthly, at TIBOR plus 0.24% to 0.38% (weighted-average of 0.32% as of March 31, 2017 ). As of March 31, 2017 , $3.1 million was available to be drawn. (5) In November 2015, we entered into a $39.0 million revolving credit facility. Principal is payable at maturity. Interest is payable monthly, at TAIFX plus a bank determined spread ( 2.54% as of March 31, 2017 ). As of March 31, 2017 , $19.0 million was available to be drawn. (6) In December 2016, we entered into a $50.0 million term loan agreement. Principal is payable in semiannual installments of $0.5 million , with the remaining balance due at maturity. Interest is payable quarterly, at LIBOR plus 1.80% ( 2.81% as of March 31, 2017 ). In January 2017, we borrowed $50.0 million . Our foreign debt is generally collateralized by the land, buildings and equipment in the respective locations. The carrying value of the collateral exceeds the carrying amount of the debt. The debt of Amkor Technology, Inc. is structurally subordinated in right of payment to all existing and future debt and other liabilities of our subsidiaries. The agreements governing our indebtedness contain affirmative and negative covenants which restrict our ability to pay dividends and could restrict our operations. We have never paid a dividend to our stockholders and we do not have any present plans for doing so. We were in compliance with all debt covenants at March 31, 2017 .

Pension Plans

Pension Plans	3 Months Ended
	Mar. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Pension Plans	Pension Plans Foreign Defined Benefit Pension Plans Our subsidiaries in Japan, Korea, Malaysia, the Philippines and Taiwan sponsor defined benefit pension plans. Charges to expense are based upon actuarial analyses. The components of net periodic pension cost for these defined benefit pension plans are as follows: For the Three Months Ended 2017 2016 (In thousands) Service cost $ 8,340 $ 8,170 Interest cost 1,007 904 Expected return on plan assets (1,128 ) (947 ) Amortization of prior service cost 31 9 Recognized actuarial loss 22 24 Net periodic pension cost $ 8,272 $ 8,160 Defined Contribution Pension Plans We sponsor defined contribution pension plans in Korea, Malaysia, Taiwan and the U.S. The following table summarizes our defined contribution expense: For the Three Months Ended 2017 2016 (In thousands) Defined contribution expense $ 3,198 $ 2,935

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The accounting framework for determining fair value includes a hierarchy for ranking the quality and reliability of the information used to measure fair value, which enables the reader of the financial statements to assess the inputs used to develop those measurements. The fair value hierarchy consists of three tiers as follows: Level 1, defined as quoted market prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, model-based valuation techniques for which all significant assumptions are observable in the market or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities and Level 3, defined as unobservable inputs that are not corroborated by market data. The fair values of cash, accounts receivable, trade accounts payable, capital expenditures payable, and certain other current assets and accrued expenses approximate carrying values because of their short-term nature. The carrying value of certain other non-current liabilities approximates fair value. Our assets and liabilities recorded at fair value on a recurring basis include cash equivalent money market funds and restricted cash money market funds. We also review goodwill for impairment annually during the fourth quarter of each year. Cash equivalent money market funds and restricted cash money market funds are invested in U.S. money market funds and various U.S. and foreign bank operating and time deposit accounts, which are due on demand or carry a maturity date of less than three months when purchased. No restrictions have been imposed on us regarding withdrawal of balances with respect to our cash equivalents as a result of liquidity or other credit market issues affecting the money market funds we invest in or the counterparty financial institutions holding our deposits. Money market funds are valued using quoted market prices in active markets for identical assets. Recurring fair value measurements consist of the following: March 31, December 31, (In thousands) Cash equivalent money market funds (Level 1) $ 78,596 $ 39,548 Restricted cash money market funds (Level 1) 2,000 2,000 We also measure certain assets and liabilities, including property, plant and equipment and goodwill, at fair value on a nonrecurring basis. We measure the fair value of our debt for disclosure purposes. The following table presents the fair value of financial instruments that are not recorded at fair value on a recurring basis: March 31, 2017 December 31, 2016 Fair Value Carrying Value Fair Value Carrying Value (In thousands) Senior notes (Level 1) $ 949,700 $ 922,330 $ 954,765 $ 922,140 Revolving credit facilities and term loans (Level 2) 599,731 600,334 551,793 552,690 Total debt $ 1,549,431 $ 1,522,664 $ 1,506,558 $ 1,474,830 The estimated fair value of our senior notes is based primarily on quoted market prices reported on or near the respective balance sheet dates. The estimated fair value of our revolving credit facilities and term loans is calculated using a discounted cash flow analysis, which utilizes market based assumptions including forward interest rates adjusted for credit risk.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies We have a letter of credit sub-limit facility of $25.0 million under our $ 200.0 million senior secured revolving credit facility that matures in December 2019. As of March 31, 2017 , we had $0.5 million of standby letters of credit outstanding, which we use in the ordinary course of our business. We generally warrant that our services will be performed in a professional and workmanlike manner and in compliance with our customers' specifications. We accrue costs for known warranty issues. Historically, our warranty costs have been immaterial. Legal Proceedings We are involved in claims and legal proceedings and may become involved in other legal matters arising in the ordinary course of our business. We evaluate these claims and legal matters on a case-by-case basis to make a determination as to the impact, if any, on our business, liquidity, results of operations, financial condition or cash flows. Although the outcome of these matters is uncertain, we believe that the ultimate outcome of these claims and proceedings, individually and in the aggregate, will not have a material adverse impact to us. Our evaluation of the potential impact of these claims and legal proceedings on our business, liquidity, results of operations, financial condition or cash flows could change in the future. In accordance with the accounting guidance for loss contingencies, including legal proceedings, lawsuits, pending claims and other legal matters, we accrue for a loss contingency when we conclude that the likelihood of a loss is probable and the amount of the loss can be reasonably estimated. We adjust our accruals from time to time as we receive additional information, but the loss we incur may be significantly greater than or less than the amount we have accrued. We disclose loss contingencies if we believe they are material and there is at least a reasonable possibility that a loss has been incurred. Attorney fees related to legal matters are expensed as incurred.

Interim Financial Statements (P

Interim Financial Statements (Policies)	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation. The Consolidated Financial Statements and related disclosures as of March 31, 2017 , and for the three months ended March 31, 2017 and 2016 , are unaudited, pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). The December 31, 2016 , Consolidated Balance Sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“U.S.”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) have been condensed or omitted pursuant to such rules and regulations. In our opinion, these financial statements include all adjustments (consisting only of normal recurring adjustments) necessary for the fair statement of the results for the interim periods. These financial statements should be read in conjunction with the financial statements included in our Annual Report for the year ended December 31, 2016 , filed on Form 10-K with the SEC on February 24, 2017. The results of operations for the three months ended March 31, 2017 , are not necessarily indicative of the results to be expected for the full year. Unless the context otherwise requires, all references to “Amkor,” “we,” “us,” “our” or the “company” are to Amkor Technology, Inc. and our subsidiaries.
Use of Estimates	Use of Estimates. The Consolidated Financial Statements have been prepared in conformity with U.S. GAAP, using management’s best estimates and judgments where appropriate. These estimates and judgments affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. The estimates and judgments will also affect the reported amounts for certain revenues and expenses during the reporting period. Actual results could differ materially from these estimates and judgments.
Goodwill	Goodwill. The balance of goodwill in our Consolidated Balance Sheets reflects adjustments for foreign currency translation.
Income Taxes	We monitor on an ongoing basis our ability to utilize our deferred tax assets and whether there is a need for a related valuation allowance. In evaluating our ability to recover our deferred tax assets in the jurisdictions from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax-planning strategies and results of recent operations. For most of our foreign deferred tax assets, we consider it more likely than not that we will have sufficient taxable income to allow us to realize these deferred tax assets. We maintain a valuation allowance on all our U.S. net deferred tax assets, including our net operating loss carryforwards. Such valuation allowances are released as the related tax benefits are realized or when sufficient evidence exists to conclude that it is more likely than not that the deferred tax assets will be realized.
Commitments and Contingencies	In accordance with the accounting guidance for loss contingencies, including legal proceedings, lawsuits, pending claims and other legal matters, we accrue for a loss contingency when we conclude that the likelihood of a loss is probable and the amount of the loss can be reasonably estimated. We adjust our accruals from time to time as we receive additional information, but the loss we incur may be significantly greater than or less than the amount we have accrued. We disclose loss contingencies if we believe they are material and there is at least a reasonable possibility that a loss has been incurred. Attorney fees related to legal matters are expensed as incurred.

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of share-based compensation costs	The following table summarizes our share-based compensation expense attributable to stock options and restricted shares: For the Three Months Ended 2017 2016 (In thousands) Share-based compensation expense $ 1,053 $ 805
Summary of all common stock option activity	The following table summarizes our stock option activity for the three months ended March 31, 2017 : Number of Shares (In thousands) Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (In thousands) Outstanding at December 31, 2016 2,443 $ 6.93 Granted 2,735 9.86 Exercised (27 ) 5.49 Forfeited or expired — — Outstanding at March 31, 2017 5,151 $ 8.49 7.96 $ 15,973 Fully vested at March 31, 2017 and expected to vest thereafter 4,962 $ 8.45 7.89 $ 15,580 Exercisable at March 31, 2017 1,671 $ 7.30 4.61 $ 7,190
Assumptions used in valuing the weighted average fair values of the options granted	For the Three Months Ended 2017 2016 Expected life (in years) 5.6 6.0 Risk-free interest rate 1.9 % 1.5 % Volatility 43 % 44 % Dividend yield — — Weighted-average grant date fair value per option granted $ 4.16 $ 2.02
Restricted share activity	The following table summarizes our restricted share activity for the three months ended March 31, 2017 : Number of Shares (In thousands) Weighted- Average Grant Date Fair Value (Per share) Non-vested at December 31, 2016 145 $ 5.02 Awards granted 200 9.86 Awards vested (47 ) 4.50 Awards forfeited — — Non-vested at March 31, 2017 298 $ 8.35

Other Income and Expense (Table

Other Income and Expense (Tables)	3 Months Ended
	Mar. 31, 2017
Other Income and Expenses [Abstract]
Schedule of Other Nonoperating Income (Expense)	Other income and expense consists of the following: For the Three Months Ended 2017 2016 (In thousands) Interest income $ (511 ) $ (404 ) Foreign currency (gain) loss, net 11,384 3,623 Other (9 ) (27 ) Other (income) expense, net $ 10,864 $ 3,192

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Computation of basic and diluted earnings per share	The following table summarizes the computation of basic and diluted EPS: For the Three Months Ended 2017 2016 (In thousands, except per share data) Net income (loss) available to Amkor common stockholders $ (10,006 ) $ (875 ) Weighted-average number of common shares outstanding — basic 238,685 237,025 Weighted-average number of common shares outstanding — diluted 238,685 237,025 Net income (loss) attributable to Amkor per common share: Basic $ (0.04 ) $ — Diluted (0.04 ) —
Antidilutive effect of potential shares of common stock that were excluded from diluted earnings per share	The following table summarizes the potential shares of common stock that were excluded from diluted EPS, because the effect of including these potential shares was anti-dilutive: For the Three Months Ended 2017 2016 (In thousands) Stock options and restricted share awards 5,449 4,033

Equity and Accumulated Other 27

Equity and Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Changes in equity attributable to both Company and noncontrolling interests	Changes in equity consist of the following: Attributable to Amkor Attributable to Non-controlling Interests Total (In thousands) Equity at December 31, 2016 $ 1,383,588 $ 19,816 $ 1,403,404 Net income (loss) (10,006 ) 862 (9,144 ) Other comprehensive income (loss) 13,816 — 13,816 Issuance of stock through employee share-based compensation plans 145 — 145 Treasury stock acquired through surrender of shares for tax withholding (210 ) — (210 ) Share-based compensation 1,053 — 1,053 Subsidiary dividends paid to non-controlling interests — (135 ) (135 ) Equity at March 31, 2017 $ 1,388,386 $ 20,543 $ 1,408,929 Attributable to Amkor Attributable to Non-controlling Interests Total (In thousands) Equity at December 31, 2015 $ 1,200,286 $ 17,250 $ 1,217,536 Net income (loss) (875 ) 470 (405 ) Other comprehensive income (loss) 19,347 — 19,347 Treasury stock acquired through surrender of shares for tax withholding (119 ) — (119 ) Share-based compensation 805 — 805 Subsidiary dividends paid to non-controlling interests — (135 ) (135 ) Equity at March 31, 2016 $ 1,219,444 $ 17,585 $ 1,237,029
Changes in accumulated other comprehensive income (loss)	Changes in accumulated other comprehensive income (loss), net of tax, consist of the following: Defined Benefit Pension Foreign Currency Translation Total (In thousands) Accumulated other comprehensive income (loss) at December 31, 2016 $ 1,138 $ 5,124 $ 6,262 Other comprehensive income (loss) before reclassifications — 13,586 13,586 Amounts reclassified from accumulated other comprehensive income (loss) 230 — 230 Other comprehensive income (loss) 230 13,586 13,816 Accumulated other comprehensive income (loss) at March 31, 2017 $ 1,368 $ 18,710 $ 20,078 Defined Benefit Pension Foreign Currency Translation Total (In thousands) Accumulated other comprehensive income (loss) at December 31, 2015 $ (1,425 ) $ (659 ) $ (2,084 ) Other comprehensive income (loss) before reclassifications — 19,323 19,323 Amounts reclassified from accumulated other comprehensive income (loss) 24 — 24 Other comprehensive income (loss) 24 19,323 19,347 Accumulated other comprehensive income (loss) at March 31, 2016 $ (1,401 ) $ 18,664 $ 17,263

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2017
Inventory Disclosure [Abstract]
Inventories	Inventories consist of the following: March 31, December 31, 2016 (In thousands) Raw materials and purchased components $ 179,932 $ 173,035 Work-in-process 87,276 94,955 Total inventories $ 267,208 $ 267,990

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of Property, plant and equipment	Property, plant and equipment consist of the following: March 31, December 31, 2016 (In thousands) Land $ 215,566 $ 240,719 Land use rights 26,845 26,845 Buildings and improvements 1,339,370 1,362,007 Machinery and equipment 4,580,400 4,483,523 Software and computer equipment 208,655 205,969 Furniture, fixtures and other equipment 22,133 21,313 Construction in progress 89,799 87,037 Total property, plant and equipment 6,482,768 6,427,413 Accumulated depreciation and amortization (3,931,062 ) (3,862,765 ) Total property, plant and equipment, net $ 2,551,706 $ 2,564,648 The following table summarizes our depreciation expense: For the Three Months Ended 2017 2016 (In thousands) Depreciation expense $ 141,456 $ 136,508

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2017
Payables and Accruals [Abstract]
Summarized Accrued expenses	Accrued expenses consist of the following: March 31, December 31, (In thousands) Payroll and benefits $ 116,526 $ 117,636 Deferred revenue and customer advances 58,873 65,653 Accrued settlement costs 35,908 35,304 Accrued interest 28,083 13,046 Income taxes payable 25,453 37,961 Accrued severance plan obligations 15,266 14,053 Other accrued expenses 58,554 55,016 Total accrued expenses $ 338,663 $ 338,669

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Summary of Short term Borrowings And Long term Debt	Following is a summary of short-term borrowings and long-term debt: March 31, December 31, (In thousands) Debt of Amkor Technology, Inc.: Senior secured credit facilities: $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due $ — $ — Senior notes: 6.625% Senior notes, due June 2021 400,000 400,000 6.375% Senior notes, due October 2022 524,971 524,971 Debt of subsidiaries: Amkor Technology Korea, Inc.: $100 million revolving credit facility, foreign currency funding-linked base rate plus 1.60%, due June 2017 (2) — — Term loan, LIBOR plus 2.60%, due May 2018 120,000 120,000 Term loan, LIBOR plus 2.70%, due December 2019 55,000 55,000 Term loan, foreign currency funding-linked base rate plus 1.32%, due May 2020 150,000 150,000 Term loan, foreign currency funding-linked base rate plus 1.33%, due May 2020 (2) 80,000 80,000 Term loan, fund floating rate plus 1.60%, due June 2020 (3) 86,000 86,000 J-Devices Corporation: Short-term term loans, variable rate (4) 22,370 22,230 Term loans, fixed rate at 0.53%, due April 2018 16,964 19,460 Other: Revolving credit facility, TAIFX plus a bank-determined spread, due 20,000 20,000 Term loan, LIBOR plus 1.80%, due December 2019 (China) (6) 50,000 — 1,525,305 1,477,661 Less: Unamortized premium and deferred debt costs, net (2,641 ) (2,831 ) Less: Short-term borrowings and current portion of long-term debt (36,927 ) (35,192 ) Long-term debt (including related party) $ 1,485,737 $ 1,439,638 (1) Our $200.0 million senior secured revolving credit facility has a letter of credit sub-limit facility of $25.0 million . Principal is payable at maturity. The availability for the revolving credit facility is based on the amount of our eligible accounts receivable, which was $166.0 million as of March 31, 2017 . Additionally, we had $ 0.5 million of standby letters of credit outstanding, resulting in $165.5 million available to be drawn as of March 31, 2017 . (2) In June 2012, we entered into a $41.0 million revolving credit facility. In March 2016, we increased the facility to $100.0 million . Principal is payable at maturity. Interest is payable monthly in arrears, at a foreign currency funding-linked base rate plus 1.60% ( 3.62% as of March 31, 2017 ). As of March 31, 2017 , $100.0 million was available to be drawn. In April 2017, we borrowed $75.0 million on this facility and repaid the outstanding balance of $80.0 million on our term loan due May 2020. (3) In May 2015, we entered into a term loan agreement pursuant to which we may borrow up to $150.0 million for capital expenditures. Principal is payable at maturity. Interest is payable quarterly in arrears, at a fund floating rate plus 1.60% ( 2.93% as of March 31, 2017 ). As of March 31, 2017 , $64.0 million was available to be borrowed. (4) We entered into various short-term term loans which mature semiannually. Principal is payable in monthly installments. Interest is payable monthly, at TIBOR plus 0.24% to 0.38% (weighted-average of 0.32% as of March 31, 2017 ). As of March 31, 2017 , $3.1 million was available to be drawn. (5) In November 2015, we entered into a $39.0 million revolving credit facility. Principal is payable at maturity. Interest is payable monthly, at TAIFX plus a bank determined spread ( 2.54% as of March 31, 2017 ). As of March 31, 2017 , $19.0 million was available to be drawn. (6) In December 2016, we entered into a $50.0 million term loan agreement. Principal is payable in semiannual installments of $0.5 million , with the remaining balance due at maturity. Interest is payable quarterly, at LIBOR plus 1.80% ( 2.81% as of March 31, 2017 ). In January 2017, we borrowed $50.0 million .

Pension Plans (Tables)

Pension Plans (Tables)	3 Months Ended
	Mar. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Components of net periodic pension cost	The components of net periodic pension cost for these defined benefit pension plans are as follows: For the Three Months Ended 2017 2016 (In thousands) Service cost $ 8,340 $ 8,170 Interest cost 1,007 904 Expected return on plan assets (1,128 ) (947 ) Amortization of prior service cost 31 9 Recognized actuarial loss 22 24 Net periodic pension cost $ 8,272 $ 8,160
Defined contribution plan disclosures	The following table summarizes our defined contribution expense: For the Three Months Ended 2017 2016 (In thousands) Defined contribution expense $ 3,198 $ 2,935

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Valuation of money market funds and restricted cash using quoted market prices in active markets for identical assets	Recurring fair value measurements consist of the following: March 31, December 31, (In thousands) Cash equivalent money market funds (Level 1) $ 78,596 $ 39,548 Restricted cash money market funds (Level 1) 2,000 2,000
Financial instruments that are not recorded at fair value	The following table presents the fair value of financial instruments that are not recorded at fair value on a recurring basis: March 31, 2017 December 31, 2016 Fair Value Carrying Value Fair Value Carrying Value (In thousands) Senior notes (Level 1) $ 949,700 $ 922,330 $ 954,765 $ 922,140 Revolving credit facilities and term loans (Level 2) 599,731 600,334 551,793 552,690 Total debt $ 1,549,431 $ 1,522,664 $ 1,506,558 $ 1,474,830

Acquisition - Narrative (Detail

Acquisition - Narrative (Details)	Feb. 28, 2017
Nanium S.A.
Business Acquisition [Line Items]
Ownership interest acquired (as a percent)	100.00%

Share-Based Compensation Plan35

Share-Based Compensation Plans - Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation expense	$ 1,053	$ 805

Share-Based Compensation Plan36

Share-Based Compensation Plans - Stock Options (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)$ / sharesshares
Number of Shares
Number of shares outstanding beginning balance | shares	2,443
Number of shares granted | shares	2,735
Number of shares exercised | shares	(27)
Number of shares forfeited or expired | shares	0
Number of shares outstanding ending balance | shares	5,151
Number of shares fully vested and expected to vest | shares	4,962
Number of shares exercisable | shares	1,671
Weighted-Average Exercise Price Per Share
Weighted average exercise price per share outstanding beginning balance (in dollars per share) | $ / shares	$ 6.93
Weighted average exercise price per share granted (in dollars per share) | $ / shares	9.86
Weighted average exercise price per share exercised (in dollars per share) | $ / shares	5.49
Weighted average exercise price per share forfeited or expired (in dollars per share) | $ / shares	0
Weighted average exercise price per share outstanding ending balance (in dollars per share) | $ / shares	8.49
Weighted average exercise price per share fully vested and expected to vest (in dollars per share) | $ / shares	8.45
Weighted average exercise price per share exercisable (in dollars per share) | $ / shares	$ 7.30
Aggregate Intrinsic Value
Weighted average remaining contractual term outstanding	7 years 11 months 16 days
Weighted average remaining contractual term fully vested and expected to vest	7 years 10 months 21 days
Weighted average remaining contractual term exercisable	4 years 7 months 10 days
Aggregate intrinsic value outstanding ending balance (in dollars) | $	$ 15,973
Aggregate intrinsic value fully vested and expected to vest (in dollars) | $	15,580
Aggregate intrinsic value exercisable (in dollars) | $	$ 7,190

Share-Based Compensation Plan37

Share-Based Compensation Plans - Weighted Average Fair Value (Details) - $ / shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected life	5 years 6 months 29 days	6 years
Risk-free interest rate	1.90%	1.50%
Volatility	43.00%	44.00%
Dividend yield	0.00%	0.00%
Weighted-average grant date fair value per option granted (in dollars per share)	$ 4.16	$ 2.02

Share-Based Compensation Plan38

Share-Based Compensation Plans - Restricted Shares (Details) - Restricted shares shares in Thousands	3 Months Ended
	Mar. 31, 2017$ / sharesshares
Number of Shares
Number of shares nonvested beginning balance | shares	145
Number of shares awards granted | shares	200
Number of shares awards vested | shares	(47)
Number of shares awards forfeited | shares	0
Number of shares nonvested ending balance | shares	298
Weighted-Average Grant Date Fair Value (Per share)
Weighted average grant-date fair value nonvested beginning balance (in dollars per share) | $ / shares	$ 5.02
Weighted average grant-date fair value awards granted (in dollars per share) | $ / shares	9.86
Weighted average grant-date fair value awards vested (in dollars per share) | $ / shares	4.50
Weighted average grant-date fair value awards forfeited (in dollars per share) | $ / shares	0
Weighted average grant-date fair value nonvested ending balance (in dollars per share) | $ / shares	$ 8.35

Share-Based Compensation Plan39

Share-Based Compensation Plans - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense from share-based compensation awards	$ 12.1
Weighted-average period of recognition of unrecognized compensation expense	3 years 5 months 13 days
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense from share-based compensation awards	$ 1.9
Weighted-average period of recognition of unrecognized compensation expense	2 years 8 months 1 day

Other Income and Expense (Detai

Other Income and Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other Income and Expenses [Abstract]
Interest income	$ (511)	$ (404)
Foreign currency (gain) loss, net	11,384	3,623
Other	(9)	(27)
Total other (income) expense, net	$ 10,864	$ 3,192

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income tax expense	$ 439	$ 1,873
Gross unrecognized tax benefits	$ 24,700		$ 23,100

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net income (loss) available to Amkor common stockholders	$ (10,006)	$ (875)
Weighted-average number of common shares outstanding — basic	238,685	237,025
Weighted-average number of common shares outstanding — diluted	238,685	237,025
Net income (loss) attributable to Amkor per common share:
Basic (in dollars per share)	$ (0.04)	$ 0
Diluted (in dollars per share)	$ (0.04)	$ 0

Earnings Per Share - Antidiluti

Earnings Per Share - Antidilutive (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Stock options and restricted shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options and restricted share awards	5,449	4,033

Equity and Accumulated Other 44

Equity and Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,403,404	$ 1,217,536
Net income (loss)	(9,144)	(405)
Other comprehensive income (loss)	13,816	19,347
Issuance of stock through employee share-based compensation plans	145
Treasury stock acquired through surrender of shares for tax withholding	(210)	(119)
Share-based compensation	1,053	805
Subsidiary dividends paid to non-controlling interests	(135)	(135)
Ending balance	1,408,929	1,237,029
Amkor
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,383,588	1,200,286
Net income (loss)	(10,006)	(875)
Other comprehensive income (loss)	13,816	19,347
Issuance of stock through employee share-based compensation plans	145
Treasury stock acquired through surrender of shares for tax withholding	(210)	(119)
Share-based compensation	1,053	805
Subsidiary dividends paid to non-controlling interests	0	0
Ending balance	1,388,386	1,219,444
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	19,816	17,250
Net income (loss)	862	470
Other comprehensive income (loss)	0	0
Issuance of stock through employee share-based compensation plans	0
Treasury stock acquired through surrender of shares for tax withholding	0	0
Share-based compensation	0	0
Subsidiary dividends paid to non-controlling interests	(135)	(135)
Ending balance	$ 20,543	$ 17,585

Equity and Accumulated Other 45

Equity and Accumulated Other Comprehensive Income (Loss) - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 1,403,404	$ 1,217,536
Total other comprehensive income (loss)	13,816	19,347
Ending balance	1,408,929	1,237,029
Defined Benefit Pension
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	1,138	(1,425)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	230	24
Total other comprehensive income (loss)	230	24
Ending balance	1,368	(1,401)
Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	5,124	(659)
Other comprehensive income (loss) before reclassifications	13,586	19,323
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Total other comprehensive income (loss)	13,586	19,323
Ending balance	18,710	18,664
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	6,262	(2,084)
Other comprehensive income (loss) before reclassifications	13,586	19,323
Amounts reclassified from accumulated other comprehensive income (loss)	230	24
Total other comprehensive income (loss)	13,816	19,347
Ending balance	$ 20,078	$ 17,263

Factoring of Accounts Receiva46

Factoring of Accounts Receivable - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Total Factored [Member]
Factoring of Accounts Receivable [Line Items]
Accounts receivable sold without recourse	$ 132.2	$ 139.1
Factoring Fees [Member]
Factoring of Accounts Receivable [Line Items]
Accounts receivable sold without recourse	$ 0.8	$ 0.4

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Inventories
Raw materials and purchased components	$ 179,932	$ 173,035
Work-in-process	87,276	94,955
Total inventories	$ 267,208	$ 267,990

Property, Plant and Equipment48

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 6,482,768	$ 6,427,413
Accumulated depreciation and amortization	(3,931,062)	(3,862,765)
Total property, plant and equipment, net	2,551,706	2,564,648
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	215,566	240,719
Land use rights
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	26,845	26,845
Buildings and improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	1,339,370	1,362,007
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	4,580,400	4,483,523
Software and computer equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	208,655	205,969
Furniture, fixtures and other equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	22,133	21,313
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 89,799	$ 87,037

Property, Plant and Equipment49

Property, Plant and Equipment (Narrative) (Details) $ in Thousands, ₩ in Billions	May 05, 2017USD ($)	May 05, 2017KRW (₩)	Nov. 30, 2016	Mar. 31, 2017USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2016USD ($)
Property, Plant and Equipment [Line Items]
Depreciation				$ 141,456	$ 136,508
Property, plant and equipment, gross				6,482,768		$ 6,427,413
Proceeds from sale of property, plant and equipment				1,835	$ 121
Assets held-for-sale, current				34,300
Korea
Property, Plant and Equipment [Line Items]
Percentage of proceeds received			10.00%
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross				89,799		87,037
Construction in progress | K5 Facility | Korea
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross				$ 46,800		$ 44,800
Subsequent Event | Korea
Property, Plant and Equipment [Line Items]
Proceeds from sale of property, plant and equipment	$ 142,000	₩ 162.1
Pre-tax gain at close	$ 108,000

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Payroll and benefits	$ 116,526	$ 117,636
Deferred revenue and customer advances	58,873	65,653
Accrued settlement costs	35,908	35,304
Accrued interest	28,083	13,046
Income taxes payable	25,453	37,961
Accrued severance plan obligations	15,266	14,053
Other accrued expenses	58,554	55,016
Total accrued expenses	$ 338,663	$ 338,669

Debt - Short-term Borrowings an

Debt - Short-term Borrowings and Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt including related party, gross	$ 1,525,305	$ 1,477,661
Less: Unamortized premium and deferred debt costs, net	(2,641)	(2,831)
Less: Short-term borrowings and current portion of long-term debt	(36,927)	(35,192)
Long-term debt (including related party)	1,485,737	1,439,638
$200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Long-term debt including related party, gross	0	0
6.625% Senior notes, due June 2021 | Senior Notes
Debt Instrument [Line Items]
Long-term debt including related party, gross	400,000	400,000
6.375% Senior notes, due October 2022 | Senior Notes
Debt Instrument [Line Items]
Long-term debt including related party, gross	524,971	524,971
Korea | $100 million revolving credit facility, foreign currency funding-linked base rate plus 1.60%, due June 2017 | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Long-term debt including related party, gross	0	0
Korea | Term loan, LIBOR plus 2.60%, due May 2018 | Subsidiary Term Loans
Debt Instrument [Line Items]
Long-term debt including related party, gross	120,000	120,000
Korea | Term loan, LIBOR plus 2.70%, due December 2019 | Subsidiary Term Loans
Debt Instrument [Line Items]
Long-term debt including related party, gross	55,000	55,000
Korea | Term loan, foreign currency funding-linked base rate plus 1.32%, due May 2020 | Subsidiary Term Loans
Debt Instrument [Line Items]
Long-term debt including related party, gross	150,000	150,000
Korea | Term loan, foreign currency funding-linked base rate plus 1.33%, due May 2020 | Subsidiary Term Loans
Debt Instrument [Line Items]
Long-term debt including related party, gross	80,000	80,000
Korea | Term loan, fund floating rate plus 1.60%, due June 2020 | Subsidiary Term Loans
Debt Instrument [Line Items]
Long-term debt including related party, gross	86,000	86,000
Japan | Short-term term loans, variable rate | Subsidiary Term Loans
Debt Instrument [Line Items]
Long-term debt including related party, gross	22,370	22,230
Japan | Term loans, fixed rate at 0.53%, due April 2018 | Subsidiary Term Loans
Debt Instrument [Line Items]
Long-term debt including related party, gross	16,964	19,460
Taiwan | Revolving credit facility, TAIFX plus a bank-determined spread, due November 2020 (Taiwan) | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Long-term debt including related party, gross	20,000	20,000
China | Term Loan, LIBOR plus 1.80%, due December 2019 (China)
Debt Instrument [Line Items]
Long-term debt including related party, gross	$ 50,000	$ 0

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)	1 Months Ended			3 Months Ended
	Apr. 30, 2017	Jan. 31, 2017	Dec. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Nov. 30, 2015	May 31, 2015	Jun. 30, 2012
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt				$ 50,000,000	$ 0
China | Term Loan, LIBOR plus 1.80%, due December 2019 (China)
Debt Instrument [Line Items]
Interest rate at period end (as a percent)				2.81%
Proceeds from issuance of long-term debt		$ 50,000,000
Amount of debt agreement			$ 50,000,000
Periodic principal payment			$ 500,000
Subsidiary Term Loans | Korea | Term loan, LIBOR plus 2.60%, due May 2018
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				2.60%
Subsidiary Term Loans | Korea | Term loan, LIBOR plus 2.70%, due December 2019
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				2.70%
Subsidiary Term Loans | Korea | Term loan, foreign currency funding-linked base rate plus 1.32%, due May 2020
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				1.32%
Subsidiary Term Loans | Korea | Term loan, foreign currency funding-linked base rate plus 1.33%, due May 2020
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				1.33%
Subsidiary Term Loans | Korea | Term loan, fund floating rate plus 1.60%, due June 2020
Debt Instrument [Line Items]
Credit facility, borrowing capacity							$ 150,000,000
Basis spread on variable rate (as a percent)				1.60%
Remaining borrowing capacity				$ 64,000,000
Interest rate at period end (as a percent)				2.93%
Subsidiary Term Loans | Japan | Short-term term loans, variable rate
Debt Instrument [Line Items]
Remaining borrowing capacity				$ 3,100,000
Subsidiary Term Loans | Japan | Term loans, fixed rate at 0.53%, due April 2018
Debt Instrument [Line Items]
Stated interest rate (as a percent)				0.53%
Senior Notes | 6.625% Senior notes, due June 2021
Debt Instrument [Line Items]
Stated interest rate (as a percent)				6.625%
Senior Notes | 6.375% Senior notes, due October 2022
Debt Instrument [Line Items]
Stated interest rate (as a percent)				6.375%
Revolving Credit Facility | Line of Credit | $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019
Debt Instrument [Line Items]
Credit facility, borrowing capacity				$ 200,000,000
Current borrowing capacity				166,000,000
Remaining borrowing capacity				165,500,000
Revolving Credit Facility | Line of Credit | Korea | $100 million revolving credit facility, foreign currency funding-linked base rate plus 1.60%, due June 2017
Debt Instrument [Line Items]
Credit facility, borrowing capacity				$ 100,000,000	$ 100,000,000			$ 41,000,000
Basis spread on variable rate (as a percent)				1.60%
Remaining borrowing capacity				$ 100,000,000
Interest rate at period end (as a percent)				3.62%
Revolving Credit Facility | Line of Credit | Taiwan | Revolving credit facility, TAIFX plus a bank-determined spread, due November 2020 (Taiwan)
Debt Instrument [Line Items]
Credit facility, borrowing capacity						$ 39,000,000
Remaining borrowing capacity				$ 19,000,000
Interest rate at period end (as a percent)				2.54%
Letter of Credit
Debt Instrument [Line Items]
Standby letters of credit outstanding				$ 500,000
Letter of Credit | $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019
Debt Instrument [Line Items]
Credit facility, borrowing capacity				$ 25,000,000
Minimum | Revolving Credit Facility | Line of Credit | $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				1.25%
Maximum | Revolving Credit Facility | Line of Credit | $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				1.75%
TIBOR | Minimum | Subsidiary Term Loans | Japan | Short-term term loans, variable rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				0.24%
TIBOR | Maximum | Subsidiary Term Loans | Japan | Short-term term loans, variable rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				0.38%
TIBOR | Weighted Average | Subsidiary Term Loans | Japan | Short-term term loans, variable rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				0.32%
LIBOR | China | Term Loan, LIBOR plus 1.80%, due December 2019 (China)
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				1.80%
Subsequent Event | Subsidiary Term Loans | Korea | Term loan, foreign currency funding-linked base rate plus 1.33%, due May 2020
Debt Instrument [Line Items]
Repayments of debt	$ 80,000,000
Subsequent Event | Revolving Credit Facility | Line of Credit | Korea | $100 million revolving credit facility, foreign currency funding-linked base rate plus 1.60%, due June 2017
Debt Instrument [Line Items]
Proceeds from lines of credit	$ 75,000,000

Pension Plans - Foreign Defined

Pension Plans - Foreign Defined Benefit Pension Plans (Details) - Foreign Pension Plans - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8,340	$ 8,170
Interest cost	1,007	904
Expected return on plan assets	(1,128)	(947)
Amortization of prior service cost	31	9
Recognized actuarial loss	22	24
Net periodic pension cost	$ 8,272	$ 8,160

Pension Plans - Narrative (Deta

Pension Plans - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Defined contribution expense	$ 3,198	$ 2,935

Fair Value Measurements - Recur

Fair Value Measurements - Recurring Fair Value Measurements (Details) - Recurring Fair Value Measurements - Level 1 - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalent money market funds (Level 1)	$ 78,596	$ 39,548
Restricted cash money market funds (Level 1)	$ 2,000	$ 2,000

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for debt	$ 1,549,431	$ 1,506,558
Fair Value | Senior notes (Level 1) | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for debt	949,700	954,765
Fair Value | Revolving credit facilities and term loans (Level 2) | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for debt	599,731	551,793
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for debt	1,522,664	1,474,830
Carrying Value | Senior notes (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for debt	922,330	922,140
Carrying Value | Revolving credit facilities and term loans (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for debt	$ 600,334	$ 552,690

Commitments and Contingencies (

Commitments and Contingencies (Details)	Mar. 31, 2017USD ($)
Letter of Credit
Loss Contingencies [Line Items]
Standby letters of credit outstanding	$ 500,000
$200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 | Letter of Credit
Loss Contingencies [Line Items]
Credit facility, borrowing capacity	25,000,000
$200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 | Line of Credit | Revolving Credit Facility
Loss Contingencies [Line Items]
Credit facility, borrowing capacity	$ 200,000,000