Summary of Significant Accounting Policies - Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014	[1]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ 0						$ 0
Revenues	$ 7,498	$ 8,179	$ 8,061	$ 8,647	9,590	$ 9,983	$ 9,363	$ 9,868	$ 32,385	[1]	38,804	[1]	$ 38,730
Additional Paid-in Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption					(675)						(675)
Accounting Standards Update 2016-09 | New Accounting Pronouncement, Early Adoption, Effect | Additional Paid-in Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ 675						$ 675
Accounting Standards Update 2014-09 | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues									$ 14,700

[1] Includes related party amounts of $1,313, $4,909, and $2,993 in 2016, 2015, and 2014, respectively. See Note 14 for additional information on related party transactions.