Guarantees and Off-Balance Sheet Arrangements Details (Tables)

9 Months Ended

Sep. 30, 2017

Guarantees and Off Balance Sheet Arrangements [Abstract]

Schedule of Subordinated Borrowing [Table Text Block]

The Company maintains uncommitted financing arrangements with large financial institutions, the details of which are summarized below as of September 30, 2017.

Lender	Contractual Amount		Available Amount		Maturity Date	Description
Pledge Lines	(dollars in thousands)
Bank of America	$	50,000	$	50,000	None	Secured DTC Pledge Line
Texas Capital Bank	75,000		75,000		None	Secured DTC Pledge Line
BMO Harris Bank	150,000		150,000		None	Secured DTC Pledge Line
Total	275,000		275,000
Revolving Credit Facility
BMO Harris Bank	30,000		30,000		August 2, 2018	Unsecured liquidity facility to cover increases in NSCC margin deposit requirements
Total Credit Lines	$	305,000	$	305,000