Balance Sheet Components (Prepaid Expenses and Other Current Assets) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Prepaid expenses and other current assets [Abstract]
Intra-period deferred tax asset	$ 26,841	$ 0
Prepaid service contracts - current portion	5,331	5,771
Deferred Costs	3,251	3,278
Prepaid marketing costs	2,812	503
Other prepaid expenses and current assets	5,854	5,716
Total prepaid expenses and other current assets	$ 44,089	$ 15,268