Related-Party Transactions	12 Months Ended
Dec. 31, 2018
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions Transactions with Goldman and CMHI Goldman is part of the lending group under the 2018 Recast Credit Facility, and has a $90.0 million, or 7.1%, total commitment. Another affiliate of Goldman was part of the lending group under the ANZ Loans (with a 2.5% participation in the Australia Term Loan and 31.8% in the New Zealand Term Loan), which the Company repaid during December 2018. Goldman was also the counterparty to the interest rate swap agreements related to the ANZ Loans as described in Note 10, which were terminated in December 2018 in connection with the extinguishment of the ANZ Loans. As a member of the previously described lending groups, the Company is required to pay certain fees to Goldman, which may include interest on borrowings, unused facility fees, letter of credit participation fees, and letter of credit facility fees. The Company paid interest expense and fees to Goldman totaling approximately $2.3 million, $0.9 million, and $2.0 million for the years ended December 31, 2018, 2017, and 2016, respectively. Interest payable to Goldman was nominal as of December 31, 2018 and December 31, 2017. Payments under the interest rate swap agreements are not included in the figures above and totaled approximately $1.2 million, $1.5 million and $1.1 million for the years ended December 31, 2018, 2017 and 2016. In addition, a swap termination fee was paid to Goldman in 2018 of $1.8 million in conjunction with the extinguishment of the ANZ Loans. In December 2018, the Company entered into a cross-currency swap with Goldman to hedge the changes in the cash flows of interest and principal payment on foreign-currency denominated intercompany loans, as further described in Note 10. Payments under the cross-currency swap agreements will not commence until 2019. From time-to-time the Company has entered into foreign exchange spot trades with Goldman to facilitate the movement of funds between our international subsidiaries and the U.S., including the funding of the previously mentioned intercompany loans. In December 2017, the Company prepaid in escrow a $0.2 million fee to Goldman for its share of the 2018 Senior Secured Credit Facilities commitment, which was related to the refinancing that occurred in tandem with the IPO. In connection with the IPO, Goldman and CMHI converted their Series B Preferred Shares into 28,808,224 and 4,432,034 common shares, respectively. After giving effect to the full exercise of the underwriters’ option to purchase additional common shares during the IPO, and after giving effect to the sale by Goldman of 5,163,716 common shares in the IPO, Goldman and CMHI owned approximately 16.7% and 3.1% of the Company’s common shares, respectively. In connection with the IPO, Goldman received a refund from the underwriters of approximately $1.6 million, which represents the underwriting discount on the gross proceeds received by the selling shareholders. In connection with the follow-on offering, Goldman sold 9,083,280 common shares, and after giving effect to the sale owned approximately 9.9% of the Company's common shares. In connection with the follow-on offering, Goldman received an underwriting fee of approximately $5.0 million, and received a refund of approximately $0.7 million representing the underwriting discount on the gross proceeds received by the selling shareholders. In November 2018, CMHI sold 4,432,034 common shares. As of December 31, 2018, CMHI no longer owned any common shares of the Company. Additionally, in December 2018, Goldman sold an additional 6,500,000 common shares of the Company, reducing their ownership to 5.6% as of December 31, 2018. Transactions with Fortress and YF ART Holdings L.P. Fortress held $48.5 million aggregate principal amount of the Senior Secured Term Loan B Facility as of December 31, 2017. The Company paid approximately $2.2 million in interest expense to Fortress during 2017. The Company also paid out principal amortization to Fortress of approximately $0.5 million in 2017. In connection with the refinancing of the Senior Secured Term Loan B Facility in January 2018, Fortress withdrew from the lending group under the 2018 Senior Secured Term Loan A. Fortress has no ongoing participation in our debt obligations as of December 31, 2018. In addition, Fortress sold all previously owned common shares of the Company during 2018. In connection with the IPO, YF ART Holdings L.P. received a refund from the underwriters of approximately $4.2 million, which represents the underwriting discount on the gross proceeds received by the selling shareholders. On March 8, 2018, YF ART Holdings L.P. entered into a financing agreement pledging 54,952,774 common shares of beneficial interest, $0.01 par value per share, representing approximately 38.6% of the Company’s issued and outstanding common shares as of March 8, 2018. YF ART Holdings L.P. used the proceeds from the financing agreement to pay in full the outstanding investment, including the preferred return on an investment vehicle affiliated with Fortress Investment Group LLC, which directly beneficially owned 7,235,529 common shares of the Company. As of December 31, 2018, Fortress no longer owns any common shares of the Company. In connection with the pledge by YF ART Holdings described above, the Company delivered a consent and acknowledgment to YF ART Holdings and the lenders under such margin loan agreement in which the Company, among other matters, agreed, subject to applicable law and stock exchange rules, not to take any actions that would adversely affect the enforcement of the rights of the lenders under the loan documents. The Company is not a party to the margin loan agreement and has no obligations thereunder. The Company also entered into an amendment of the shareholders agreement, which addresses certain matters related to the margin loan agreement and related documents.

Related-Party Transactions

Transactions with Goldman and CMHI

Goldman is part of the lending group under the 2018 Recast Credit Facility, and has a $90.0 million, or 7.1%, total commitment. Another affiliate of Goldman was part of the lending group under the ANZ Loans (with a 2.5% participation in the Australia Term Loan and 31.8% in the New Zealand Term Loan), which the Company repaid during December 2018. Goldman was also the counterparty to the interest rate swap agreements related to the ANZ Loans as described in Note 10, which were terminated in December 2018 in connection with the extinguishment of the ANZ Loans.

As a member of the previously described lending groups, the Company is required to pay certain fees to Goldman, which may include interest on borrowings, unused facility fees, letter of credit participation fees, and letter of credit facility fees. The Company paid interest expense and fees to Goldman totaling approximately $2.3 million, $0.9 million, and $2.0 million for the years ended December 31, 2018, 2017, and 2016, respectively. Interest payable to Goldman was nominal as of December 31, 2018 and December 31, 2017. Payments under the interest rate swap agreements are not included in the figures above and totaled approximately $1.2 million, $1.5 million and $1.1 million for the years ended December 31, 2018, 2017 and 2016. In addition, a swap termination fee was paid to Goldman in 2018 of $1.8 million in conjunction with the extinguishment of the ANZ Loans.

In December 2018, the Company entered into a cross-currency swap with Goldman to hedge the changes in the cash flows of interest and principal payment on foreign-currency denominated intercompany loans, as further described in Note 10. Payments under the cross-currency swap agreements will not commence until 2019. From time-to-time the Company has entered into foreign exchange spot trades with Goldman to facilitate the movement of funds between our international subsidiaries and the U.S., including the funding of the previously mentioned intercompany loans.

In December 2017, the Company prepaid in escrow a $0.2 million fee to Goldman for its share of the 2018 Senior Secured Credit Facilities commitment, which was related to the refinancing that occurred in tandem with the IPO. In connection with the IPO, Goldman and CMHI converted their Series B Preferred Shares into 28,808,224 and 4,432,034 common shares, respectively. After giving effect to the full exercise of the underwriters’ option to purchase additional common shares during the IPO, and after giving effect to the sale by Goldman of 5,163,716 common shares in the IPO, Goldman and CMHI owned approximately 16.7% and 3.1% of the Company’s common shares, respectively. In connection with the IPO, Goldman received a refund from the underwriters of approximately $1.6 million, which represents the underwriting discount on the gross proceeds received by the selling shareholders.

In connection with the follow-on offering, Goldman sold 9,083,280 common shares, and after giving effect to the sale owned approximately 9.9% of the Company's common shares. In connection with the follow-on offering, Goldman received an underwriting fee of approximately $5.0 million, and received a refund of approximately $0.7 million representing the underwriting discount on the gross proceeds received by the selling shareholders.

In November 2018, CMHI sold 4,432,034 common shares. As of December 31, 2018, CMHI no longer owned any common shares of the Company. Additionally, in December 2018, Goldman sold an additional 6,500,000 common shares of the Company, reducing their ownership to 5.6% as of December 31, 2018.

Transactions with Fortress and YF ART Holdings L.P.

Fortress held $48.5 million aggregate principal amount of the Senior Secured Term Loan B Facility as of December 31, 2017. The Company paid approximately $2.2 million in interest expense to Fortress during 2017. The Company also paid out principal amortization to Fortress of approximately $0.5 million in 2017. In connection with the refinancing of the Senior Secured Term Loan B Facility in January 2018, Fortress withdrew from the lending group under the 2018 Senior Secured Term Loan A. Fortress has no ongoing participation in our debt obligations as of December 31, 2018. In addition, Fortress sold all previously owned common shares of the Company during 2018.

In connection with the IPO, YF ART Holdings L.P. received a refund from the underwriters of approximately $4.2 million, which represents the underwriting discount on the gross proceeds received by the selling shareholders.

On March 8, 2018, YF ART Holdings L.P. entered into a financing agreement pledging 54,952,774 common shares of beneficial interest, $0.01 par value per share, representing approximately 38.6% of the Company’s issued and outstanding common shares as of March 8, 2018. YF ART Holdings L.P. used the proceeds from the financing agreement to pay in full the outstanding investment, including the preferred return on an investment vehicle affiliated with Fortress Investment Group LLC, which directly beneficially owned 7,235,529 common shares of the Company. As of December 31, 2018, Fortress no longer owns any common shares of the Company.

In connection with the pledge by YF ART Holdings described above, the Company delivered a consent and acknowledgment to YF ART Holdings and the lenders under such margin loan agreement in which the Company, among other matters, agreed, subject to applicable law and stock exchange rules, not to take any actions that would adversely affect the enforcement of the rights of the lenders under the loan documents. The Company is not a party to the margin loan agreement and has no obligations thereunder. The Company also entered into an amendment of the shareholders agreement, which addresses certain matters related to the margin loan agreement and related documents.