Related Party Transactions - (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
	May. 28, 2010	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014	Jun. 24, 2013	May. 29, 2012
Related Party Transactions [Line Items]
Subordinated Debt		$ 19,624	$ 19,624	$ 18,491
5% Unsecured Subordinated Notes		19,624	19,624	$ 18,491
Subordinated debt interest rate	5.00%
Kanders GMP Holdings, LLC [Member]
Related Party Transactions [Line Items]
Subordinated Debt	$ 14,517					$ 365
Interest paid on transferred subordinated note		181	544
Interest paid on Gregory employees subordinated notes		5	14
5% Unsecured Subordinated Notes	14,517					365
Discounted subordinated notes	8,640
Schiller Gregory Investment Company, LLC [Member]
Related Party Transactions [Line Items]
Subordinated Debt	7,539					189
Interest paid on Gregory employees subordinated notes		2	7
5% Unsecured Subordinated Notes	7,539					$ 189
Discounted subordinated notes	4,487
Former Employees [Member]
Related Party Transactions [Line Items]
Subordinated Debt	554
5% Unsecured Subordinated Notes	554
Discounted subordinated notes	$ 316
Robert R. Schiller 2013 Cornerstone Trust and the Deborah Schiller 2005 Revocable Trust [Member]
Related Party Transactions [Line Items]
Interest paid on transferred subordinated note		$ 95	$ 283
Robert R. Schiller 2013 Cornerstone Trust [Member]
Related Party Transactions [Line Items]
Subordinated Debt					$ 3,769
5% Unsecured Subordinated Notes					$ 3,769