DEFINED BENEFIT PLANS	3 Months Ended
Mar. 31, 2019
Retirement Benefits [Abstract]
DEFINED BENEFIT PLANS	DEFINED BENEFIT PLANS The Company maintains defined benefit pension plans that cover certain employees in Austria, France, Japan, Germany and Switzerland. Net periodic benefit costs for the Company’s defined benefit pension plans for the three months ended March 31, 2019 and 2018 were $0.5 million and $0.6 million, respectively. The components of the net periodic benefit costs other than the service cost component of $0.7 million for the three months ended March 31, 2019 and 2018, respectively, are included in other income (expense), net in the consolidated statements of operations. The Company previously disclosed in its consolidated financial statements for the year ended December 31, 2018 that it expected to contribute $1.9 million to its defined benefit pension plans in 2019. For the three months ended March 31, 2019, the Company did not make a contribution to the defined benefit plans. As of March 31, 2019, the Company anticipates contributing $1.9 million to its defined benefit plans in 2019. The estimated fair values of plan assets were $30.1 million and $31.1 million as of March 31, 2019 and December 31, 2018, respectively. The net plan assets of the pension plans are invested in common trusts as of March 31, 2019 and December 31, 2018. Common trusts are classified as Level 2 in the fair value hierarchy. The fair value of common trusts is valued at the net asset value based on the fair values of the underlying investments of the trusts as determined by the sponsor of the trusts. The investment strategy of the Company's defined benefit plans is both to meet the liabilities of the plans as they fall due and to maximize the return on invested assets within an appropriate risk profile.

DEFINED BENEFIT PLANS

The Company maintains defined benefit pension plans that cover certain employees in Austria, France, Japan, Germany and Switzerland.

Net periodic benefit costs for the Company’s defined benefit pension plans for the three months ended March 31, 2019 and 2018 were $0.5 million and $0.6 million, respectively. The components of the net periodic benefit costs other than the service cost component of $0.7 million for the three months ended March 31, 2019 and 2018, respectively, are included in other income (expense), net in the consolidated statements of operations.

The Company previously disclosed in its consolidated financial statements for the year ended December 31, 2018 that it expected to contribute $1.9 million to its defined benefit pension plans in 2019. For the three months ended March 31, 2019, the Company did not make a contribution to the defined benefit plans. As of March 31, 2019, the Company anticipates contributing $1.9 million to its defined benefit plans in 2019.

The estimated fair values of plan assets were $30.1 million and $31.1 million as of March 31, 2019 and December 31, 2018, respectively. The net plan assets of the pension plans are invested in common trusts as of March 31, 2019 and December 31, 2018. Common trusts are classified as Level 2 in the fair value hierarchy. The fair value of common trusts is valued at the net asset value based on the fair values of the underlying investments of the trusts as determined by the sponsor of the trusts. The investment strategy of the Company's defined benefit plans is both to meet the liabilities of the plans as they fall due and to maximize the return on invested assets within an appropriate risk profile.