Summary of Significant Accounting Policies - Debt Issuance Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Line Items]
Amortization of debt issuance costs	$ 778	$ 627	$ 1,153
Amortization of building financing costs	124	$ 31	$ 0
Write-off of unamortized debt issuance cost	$ 3,005
Debt Issuance Cost [Member] | Minimum [Member]
Accounting Policies [Line Items]
Debt Issuance Costs, Amortization Period (in years)	5 years
Debt Issuance Cost [Member] | Maximum [Member]
Accounting Policies [Line Items]
Debt Issuance Costs, Amortization Period (in years)	7 years
Building Financing Cost [Member]
Accounting Policies [Line Items]
Deferred Building Financing Costs, Amortization Period (in years)	25 years