Commitments and Contingencies (Narrative) (Details) ft² in Thousands, $ in Thousands		3 Months Ended
	Feb. 03, 2016 ft²	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Jun. 12, 2013
Operating Leased Assets [Line Items]
Rent expense		$ 800	$ 600
Operating Leases, Future Minimum Payments Due, Base Rent Increases [Abstract]
2015				3.00%
2016				3.00%
2017				3.00%
2018				3.00%
2019				3.00%
2020 and thereafter				4.00%
Settlement costs from litigation		4,650	0
Operating Expenses		66,345	$ 36,569
Contract Termination
Operating Leases, Future Minimum Payments Due, Base Rent Increases [Abstract]
Operating Expenses		$ 1,600
TriVascular Technologies, Inc.
Operating Leased Assets [Line Items]
Renewal term	5 years
Minimum
Operating Leased Assets [Line Items]
Severance payment, prior to change in control		6 months
Severance payment, period following change in control		18 months
Maximum
Operating Leased Assets [Line Items]
Severance payment, prior to change in control		18 months
Severance payment, period following change in control		24 months
Manufacturing Facility | TriVascular Technologies, Inc.
Operating Leased Assets [Line Items]
Aggregate square feet | ft²	110