Summary Of Business And Significant Accounting Policies Summary of Business And Significant Accounting Policies (Share Based Compensation Restatement Adjustments) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	$ 7,533,000	$ 4,813,000	$ 13,524,000	$ 9,249,000
Restricted Stock Units
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	4,900,000	3,000,000	8,700,000	5,600,000
Total unrecognized compensation cost related to unvested stock	24,900,000		24,900,000
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	8,851,000		14,842,000
Scenario, Previously Reported [Member] | Restricted Stock Units
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	6,200,000		10,000,000
Total unrecognized compensation cost related to unvested stock	37,500,000		37,500,000
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	(1,318,000)		(1,318,000)
Restatement Adjustment [Member] | Restricted Stock Units
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	(1,300,000)		(1,300,000)
Total unrecognized compensation cost related to unvested stock	(12,600,000)		(12,600,000)
Cost of revenues
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	1,818,000	898,000	2,968,000	1,699,000
Cost of revenues | Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	1,818,000		2,968,000
Cost of revenues | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	0		0
Technology and development
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	621,000	295,000	1,106,000	342,000
Technology and development | Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	659,000		1,144,000
Technology and development | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	(38,000)		(38,000)
Sales and marketing
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	738,000	668,000	1,446,000	1,332,000
Sales and marketing | Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	791,000		1,498,000
Sales and marketing | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	(53,000)		(52,000)
General and administrative
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	4,356,000	$ 2,952,000	8,004,000	$ 5,876,000
General and administrative | Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	5,583,000		9,232,000
General and administrative | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	$ (1,227,000)		$ (1,228,000)