Debt	6 Months Ended
Jun. 30, 2017
Debt Disclosure [Abstract]
Debt	Debt Credit Facilities The Company has revolving lines of credit with various banks in the United States and Europe. Total available credit at June 30, 2017, was $304.0 million including revolving credit lines and an irrevocable standby letter of credit in support of various insurance deductibles. The Company’s primary credit facility is a revolving line of credit with $300 million in available credit. On July 25, 2016, the Company entered into a second amendment (the "Amendment") to the credit facility. For additional information about the Amendment, see the Company's Current Report on Form 8-K dated July 28, 2016. As amended, this credit facility will expire on July 23, 2021. Amounts borrowed under this credit facility bear interest at an annual rate equal to either, at the Company’s option, (a) the rate for Eurocurrency deposits for the corresponding deposits of U.S. dollars appearing on Reuters LIBOR1screen page (the “LIBOR Rate”), adjusted for any reserve requirement in effect, plus a spread of 0.60% to 1.45%, determined quarterly based on the Company’s leverage ratio (at June 30, 2017, the LIBOR Rate was 1.17%), or (b) a base rate, plus a spread of 0.00% to 0.45%, determined quarterly based on the Company’s leverage ratio. The base rate is defined in a manner such that it will not be less than the LIBOR Rate. The Company will pay fees for standby letters of credit at an annual rate equal to the applicable spread described above, and will pay market-based fees for commercial letters of credit. The Company is required to pay an annual facility fee of 0.15% to 0.30% of the available commitments under the credit facility, regardless of usage, with the applicable fee determined on a quarterly basis based on the Company’s leverage ratio. The Company was also required to pay customary fees as specified in a separate fee agreement to the agent under the credit facility. The Company’s unused borrowing capacity under other revolving credit lines and a term note totaled $4.0 million at June 30, 2017. The other revolving credit lines and the term note charge interest ranging from 0.47% to 8.25%, currently have maturity dates from July 2017 to December 2017. The Company had no outstanding debt balance as of June 30, 2017 and 2016, and December 31, 2016, respectively. The Company was in compliance with its financial covenants at June 30, 2017. Capital Lease Obligation In March 2017, the Company leased office equipment from Cisco Systems Capital Corporation for four years, with lease payments totaling approximately $2.3 million through May 2021. At the inception of the lease, the Company evaluated the agreement and determined it to be a capital lease. Accordingly, the leased equipment was capitalized and a liability of $2.2 million was recorded. The terms of the lease considered in such evaluation included the transfer of ownership of the equipment to the Company at the end of the lease, a bargain purchase option, the exercise of which can be reasonably assured, and the sum of present value of lease payments, and the leased equipment's residual value amounting to substantially all of its fair value at the end of the lease. As of June 30, 2017, the current portion of the outstanding liability for the leased equipment was approximately $0.5 million and the long-term portion was approximately $1.5 million.

Debt

Credit Facilities

The Company has revolving lines of credit with various banks in the United States and Europe. Total available credit at June 30, 2017, was $304.0 million including revolving credit lines and an irrevocable standby letter of credit in support of various insurance deductibles.

The Company’s primary credit facility is a revolving line of credit with $300 million in available credit. On July 25, 2016, the Company entered into a second amendment (the "Amendment") to the credit facility. For additional information about the Amendment, see the Company's Current Report on Form 8-K dated July 28, 2016. As amended, this credit facility will expire on July 23, 2021. Amounts borrowed under this credit facility bear interest at an annual rate equal to either, at the Company’s option, (a) the rate for Eurocurrency deposits for the corresponding deposits of U.S. dollars appearing on Reuters LIBOR1screen page (the “LIBOR Rate”), adjusted for any reserve requirement in effect, plus a spread of 0.60% to 1.45%, determined quarterly based on the Company’s leverage ratio (at June 30, 2017, the LIBOR Rate was 1.17%), or (b) a base rate, plus a spread of 0.00% to 0.45%, determined quarterly based on the Company’s leverage ratio. The base rate is defined in a manner such that it will not be less than the LIBOR Rate. The Company will pay fees for standby letters of credit at an annual rate equal to the applicable spread described above, and will pay market-based fees for commercial letters of credit. The Company is required to pay an annual facility fee of 0.15% to 0.30% of the available commitments under the credit facility, regardless of usage, with the applicable fee determined on a quarterly basis based on the Company’s leverage ratio. The Company was also required to pay customary fees as specified in a separate fee agreement to the agent under the credit facility. The Company’s unused borrowing capacity under other revolving credit lines and a term note totaled $4.0 million at June 30, 2017. The other revolving credit lines and the term note charge interest ranging from 0.47% to 8.25%, currently have maturity dates from July 2017 to December 2017. The Company had no outstanding debt balance as of June 30, 2017 and 2016, and December 31, 2016, respectively. The Company was in compliance with its financial covenants at June 30, 2017.

Capital Lease Obligation

In March 2017, the Company leased office equipment from Cisco Systems Capital Corporation for four years, with lease payments totaling approximately $2.3 million through May 2021. At the inception of the lease, the Company evaluated the agreement and determined it to be a capital lease. Accordingly, the leased equipment was capitalized and a liability of $2.2 million was recorded. The terms of the lease considered in such evaluation included the transfer of ownership of the equipment to the Company at the end of the lease, a bargain purchase option, the exercise of which can be reasonably assured, and the sum of present value of lease payments, and the leased equipment's residual value amounting to substantially all of its fair value at the end of the lease.

As of June 30, 2017, the current portion of the outstanding liability for the leased equipment was approximately $0.5 million and the long-term portion was approximately $1.5 million.