Fair Value Measurement (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets:
Short-term investments	$ 117,951	$ 82,847
Foreign currency forward exchange contracts not accounted for using hedge accounting	86	123
Total assets	118,038	82,970
Liabilities:
Interest rate swaps	1,260	1,026
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Short-term investments	0	0
Foreign currency forward exchange contracts not accounted for using hedge accounting	0	0
Total assets	0	0
Liabilities:
Interest rate swaps	0	0
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Short-term investments	117,951	82,847
Foreign currency forward exchange contracts not accounted for using hedge accounting	86	123
Total assets	118,038	82,970
Liabilities:
Interest rate swaps	1,260	1,026
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Short-term investments	0	0
Foreign currency forward exchange contracts not accounted for using hedge accounting	0	0
Total assets	0	0
Liabilities:
Interest rate swaps	$ 0	$ 0