Selected Balance Sheet Components - Amortization Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Intangible assets, net
Intangible assets	$ 2,917,000
Amortization expense	300,000	$ 200,000	$ 0
Estimated future amortization expense
2016	280,000
2017	280,000
2018	280,000
2019	280,000
2020	280,000
Thereafter	1,517,000
Intangible assets	2,917,000
Commercial rights
Intangible assets, net
Gross amount	3,360,000	3,360,000
Accumulated amortization	(443,000)	(163,000)
Intangible assets	2,917,000	3,197,000
Estimated future amortization expense
Intangible assets	$ 2,917,000	$ 3,197,000