Fair Value (Details) (USD $)	Mar. 29, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange forward contract assets	$ 257,000
Total assets measured and recorded at fair value	187,352,000	168,078,000
Foreign exchange forward contracts liabilities		514,000
Total liabilities measured and recorded at fair value	1,282,000	1,796,000
Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration obligation	1,282,000	1,282,000
Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange forward contract assets	257,000	0
Foreign exchange forward contracts liabilities	0	514,000
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	49,988,000
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	187,095,000	118,090,000
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	187,095,000	118,090,000
Total liabilities measured and recorded at fair value	0	0
Fair Value, Inputs, Level 1 | Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration obligation	0	0
Fair Value, Inputs, Level 1 | Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange forward contract assets	0	0
Foreign exchange forward contracts liabilities	0	0
Fair Value, Inputs, Level 1 | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Fair Value, Inputs, Level 1 | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	187,095,000	118,090,000
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	257,000	49,988,000
Total liabilities measured and recorded at fair value	0	514,000
Fair Value, Inputs, Level 2 | Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration obligation	0	0
Fair Value, Inputs, Level 2 | Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange forward contract assets	257,000	0
Foreign exchange forward contracts liabilities	0	514,000
Fair Value, Inputs, Level 2 | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	49,988,000
Fair Value, Inputs, Level 2 | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0	0
Total liabilities measured and recorded at fair value	1,282,000	1,282,000
Fair Value, Inputs, Level 3 [Member] | Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration obligation	1,282,000	1,282,000
Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange forward contract assets	0	0
Foreign exchange forward contracts liabilities	0	0
Fair Value, Inputs, Level 3 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 0	$ 0