Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Effective tax rate	12.70%	24.50%	18.50%	26.40%
Accrued interest	$ 5,000,000		$ 5,000,000
Accrued penalties	0		0
Tax benefit from subsidiary	$ 3,000,000		$ 5,000,000		$ 13,000,000