Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Summary of Effect of Applying Guidance on Consolidated Statements of Cash Flows

The following table shows the effects of applying the guidance:

	Prior to Adoption (1)			As Adjusted
Year ended December 31, 2015:
(Accretion of discount) amortization of premium on investments	$	14,207		$	14,483
Accrued liabilities		22,453			272,065
Net cash flows used in operating activities		(251,942	)		(1,646	)
Change in restricted funds		(3,856	)		—
Proceeds from maturity of investment securities		1,894,562			1,999,421
Purchase of investment securities		(892,577	)		(1,192,873	)
Net cash flows provided by (used in) investing activities		77,460			(114,121	)
Increase (decrease) in cash, cash equivalents and restricted cash		(178,550	)		(119,835	)
Cash, cash equivalents and restricted cash, end of year		80,171			138,886
Year ended December 31, 2014:
(Accretion of discount) amortization of premium on investments		18,159			20,925
Net cash flows used in operating activities		(64,526	)		(61,760	)
Change in restricted funds		43,667			—
Proceeds from maturity of investment securities		1,700,123			2,350,705
Purchase of investment securities		(2,129,453	)		(2,739,134	)
Net cash flows provided by (used in) investing activities		(1,138,393	)		(1,141,159	)

⁽¹⁾ Amounts are after reclassification of Angolan operations to no longer reflect these operations as discontinued.