Bank Call Loans - Summary of Bank Call Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Abstract]
Year-end balance	$ 100,200	$ 59,400
Short-term Debt, Weighted Average Interest Rate	1.56%	1.22%
Maximum balance (at any month-end)	$ 189,000	$ 197,000
Average amount outstanding (during the year)	$ 116,267	$ 108,235
Average interest rate (during the year)	1.28%	1.26%