Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Loss By Component) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated other comprehensive income loss [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning balance	$ (9,094)	$ (10,536)	$ (13,450)
Other comprehensive gain (loss) before reclassifications	(3,281)	1,442	2,382
Amounts reclassified from accumulated other comprehensive loss	2,900		532
Other comprehensive income (loss)	(381)	1,442	2,914
Accumulated other comprehensive income (loss), net of tax, ending balance	(9,475)	(9,094)	(10,536)
Foreign currency translaction adjustments [Member]
Accumulated other comprehensive income loss [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning balance	(8,090)	(8,681)	(9,674)
Other comprehensive gain (loss) before reclassifications	(4,528)	591	993
Amounts reclassified from accumulated other comprehensive loss	2,930		0
Other comprehensive income (loss)	(1,598)	591	993
Accumulated other comprehensive income (loss), net of tax, ending balance	(9,688)	(8,090)	(8,681)
Unrealized loss on investments, net of tax [Member]
Accumulated other comprehensive income loss [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning balance	(1,433)	(1,851)	(3,327)
Other comprehensive gain (loss) before reclassifications	1,369	418	1,476
Amounts reclassified from accumulated other comprehensive loss	0		0
Other comprehensive income (loss)	1,369	418	1,476
Accumulated other comprehensive income (loss), net of tax, ending balance	(64)	(1,433)	(1,851)
Other [Member]
Accumulated other comprehensive income loss [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning balance	429	(4)	(449)
Other comprehensive gain (loss) before reclassifications	(122)	433	(87)
Amounts reclassified from accumulated other comprehensive loss	(30)		532
Other comprehensive income (loss)	(152)	433	445
Accumulated other comprehensive income (loss), net of tax, ending balance	$ 277	$ 429	$ (4)