Fair Value Measurements (Summary Of Valuation Of Company's Financial Instruments By Various Levels) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		$ 110,502	$ 122,719
Liabilities, Fair value		451	447
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		107,297	120,303
Liabilities, Fair value		0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		3,205	2,416
Liabilities, Fair value		451	447
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0
Liabilities, Fair value		0	0
Foreign Currency Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	[1]	3,205	2,416
Liabilities, Fair value	[2]	451	447
Foreign Currency Forward Contracts [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0
Liabilities, Fair value		0	0
Foreign Currency Forward Contracts [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		3,205	2,416
Liabilities, Fair value		451	447
Foreign Currency Forward Contracts [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0
Liabilities, Fair value		0	0
Money Market Funds [Member] | Cash Equivalents [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		10,976	4,408
Money Market Funds [Member] | Cash Equivalents [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0
Money Market Funds [Member] | Cash Equivalents [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0
Money Market Funds [Member] | Available-For-Sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		10,976	4,408
Treasuries [Member] | Available-For-Sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	[3]	94,993	114,935
Treasuries [Member] | Available-For-Sale Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		94,993	114,935
Treasuries [Member] | Available-For-Sale Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0
Treasuries [Member] | Available-For-Sale Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0
Certificates Of Deposits [Member] | Available-For-Sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	[3]	147	158
Certificates Of Deposits [Member] | Available-For-Sale Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		147	158
Certificates Of Deposits [Member] | Available-For-Sale Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0	[3]
Certificates Of Deposits [Member] | Available-For-Sale Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0	[3]
Mutual Funds [Member] | Trading Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	[3]	1,181	802
Mutual Funds [Member] | Trading Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		1,181	802
Mutual Funds [Member] | Trading Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		0	0
Mutual Funds [Member] | Trading Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value		$ 0	$ 0

[1] Included in prepaid expenses and other current assets on the Company's consolidated balance sheet.

[2] Included in other accrued liabilities on the Company's consolidated balance sheet.

[3] Included in short-term investments on the Company's consolidated balance sheet.