Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2017

Investments, Debt and Equity Securities [Abstract]

Schedule of Realized Gain (Loss)

	Three Months Ended September 30,			Nine Months Ended September 30,
	2016			2016
Proceeds from sales and maturities of securities	$	360,506		$	662,938
Gross realized gains	52,414			53,755
Gross realized losses	(13		)	(35		)