Income Taxes (Deferred) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets
Deferred revenue	$ 6,309	$ 4,140
Prepaid expenses and accruals	1,363	544
Deferred rent and lease incentives	3,940	3,521
Net operating loss and tax credit carryforwards	100,471	101,762
Property and equipment and intangible assets	(90,222)	(104,017)
Stock-based compensation expense	10,641	10,716
Investment in ERS, LLC	75
Convertible notes	(6,346)	(8,284)
Other	(2,176)	(2,201)
Total deferred tax assets	24,055	6,181
Valuation allowance for net deferred tax assets	(29,610)	(3,493)
Net deferred tax assets		$ 2,688
Net deferred tax (liabilities)	$ (5,555)