Credit Facility (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Credit Facility
Credit Facility
Amortization and interest expense capitalized	$ 234	$ 276
Amortization and interest expense expensed	$ 56
Interest rate percentage	3.50%
Amortization of debt issuance costs
April 1, 2017 - December 31, 2017	$ 182
January 1, 2018 - December 31, 2018	216
Amortization of debt issuance costs	$ 398
Credit Facility | LIBOR | Minimum
Credit Facility
Spread on floating interest rate (as a percent)	2.50%
Credit Facility | LIBOR | Maximum
Credit Facility
Spread on floating interest rate (as a percent)	3.50%
Credit Facility | Prime Rate | Minimum
Credit Facility
Spread on floating interest rate (as a percent)	1.50%
Credit Facility | Prime Rate | Maximum
Credit Facility
Spread on floating interest rate (as a percent)	2.50%
Revolving Line of Credit
Credit Facility
Current issued borrowing capacity	$ 69,750
Maximum borrowing capacity with an option to increase the available amount upon the satisfaction of certain conditions	86,500
Outstanding balance	$ 10,000		$ 15,000
Revolving Line of Credit | Minimum
Credit Facility
Fee on unused portion of Revolving Line of Credit (as a percent)	0.375%
Revolving Line of Credit | Maximum
Credit Facility
Fee on unused portion of Revolving Line of Credit (as a percent)	0.50%
Term Loan
Credit Facility
Current issued borrowing capacity	$ 3,500
Outstanding balance	$ 1,531		$ 1,969
Term of the debt	4 years
Principal payments of Term Loan
April 1, 2017 - December 31, 2017	$ 656
January 1, 2018 - December 31, 2018	875
Total	$ 1,531