Borrowings - Senior Notes (Details) $ in Thousands	Mar. 22, 2011 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Senior notes		$ 88,385	$ 85,937
Post-Modification Notes [Member]
Debt Instrument [Line Items]
Senior notes		$ 88,400	$ 85,900
Senior Notes [Member] | Post-Modification Notes [Member]
Debt Instrument [Line Items]
Face amount of debt	$ 85,900
Senior Notes [Member] | Post-Modification Notes [Member] | Interest Rate, Pre-Trigger [Member]
Debt Instrument [Line Items]
Interest rate	1.00%
Senior Notes [Member] | Post-Modification Notes [Member] | Modification Trigger, One [Member]
Debt Instrument [Line Items]
Proceeds from equity offering, minimum	$ 40,000
Senior Notes [Member] | Post-Modification Notes [Member] | Interest Rate, Post-Trigger [Member]
Debt Instrument [Line Items]
Variable rate, description	three-month LIBOR
Basis spread on variable rate	3.50%
Restriction Release Trigger, One [Member] | Senior Notes [Member] | Post-Modification Notes [Member]
Debt Instrument [Line Items]
Tangible net worth, minimum	$ 40,000
Restriction Release Trigger, Two [Member] | Senior Notes [Member] | Post-Modification Notes [Member]
Debt Instrument [Line Items]
Interest coverage ratio, minimum	1.35
Leverage ratio, maximum	95.00%