Stock-based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 07, 2014	Jul. 24, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Weighted Average Grant Date Fair Value
Non-cash share compensation					$ 2,929	$ 1,681
2013 Plan | Restricted common shares
Stock-based compensation
Maximum number of shares authorized	2,450,000	600,000
Increase in number of common shares authorized for issuance	1,850,000
Grant date value		$ 2,900			$ 2,100		$ 2,100
Vesting period		3 years					1 year
Shares
Non-vested at the beginning of the period (in shares)					319,654
Granted (in shares)		250,000			129,277		152,987
Vested (in shares)					(169,259)
Non-vested at the beginning of the period (in shares)			279,672		279,672		319,654
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)					$ 12.60
Grant date value (in dollars per share)		$ 11.50			16.18
Vested (in dollars per share)					12.91
Non-vested at beginning of period (in dollars per share)			$ 14.07		$ 14.07		$ 12.60
Non-cash share compensation			$ 700	$ 600	$ 2,200	$ 1,500
Unrecognized compensation expense			$ 2,300		$ 2,300
Initial estimated cumulative forfeiture rate (as a percent)					0.00%
2013 Plan | Restricted common shares | Management
Stock-based compensation
Vesting period					1 year
2013 Plan | Restricted common shares | Trust Employees
Stock-based compensation
Vesting period					3 years