Commitment and Contingencies - Operating Leases (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($) item	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) item	Dec. 31, 2013 USD ($)
Operating Leases
Lease Term	6 years
As Lessor
Remainder of 2016	$ 9,380
2017	12,507
2018	12,507
2019	12,507
2020	11,351
Thereafter	7,441
Total future minimum lease payments	65,693
As Lessee
Remainder of 2016	9,029
2017	12,036
2018	11,811
2019	10,622
2020	9,488
Thereafter	5,876
Total future minimum lease payments	58,862
Rental expense and rental income for all operating leases
Rental expense for all operating lease	3,000	$ 900
Cash received for future services	14,500		$ 15,100
Aggregate sale price in sale-leaseback transaction				$ 4,500
Cash received in sale-leaseback transaction	2,400		2,500
Cash held in escrow deposit	46,800
Letter of credit with Silicon Valley Bank	1,000
Other assets.
Rental expense and rental income for all operating leases
Prepaid rent and security deposit	$ 12,100		$ 12,100
Credit risk | Accounts receivable.
Rental expense and rental income for all operating leases
Number of customers | item	2		2
Concentration risk (as a percent)	42.60%		50.90%
Customer one | Credit risk | Accounts receivable.
Rental expense and rental income for all operating leases
Concentration risk (as a percent)	22.00%		38.50%
Customer two | Credit risk | Accounts receivable.
Rental expense and rental income for all operating leases
Concentration risk (as a percent)	20.60%		12.40%
Walmart | Customer concentration | Revenues.
Rental expense and rental income for all operating leases
Concentration risk (as a percent)	47.70%	63.50%