Income Taxes - Unrecognized Tax Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 400,000	$ 400,000	$ 600,000
Lapse of statute of limitations	(200,000)	0	(200,000)
Balance at end of year	200,000	400,000	400,000
Total gross amount of unrecognized tax benefits that would impact effective tax rate	200,000	400,000
The expiration of the statute of limitations for certain tax positions in future years and expected settlement of certain tax audit that could impact unrecognized tax benefits	200,000
Income taxes benefit related to recovery of interest associated with expiration of statute of limitations for certain unrecognized tax position	100,000	0	$ 200,000
Estimated interest and penalties related to unrecognized tax benefits	$ 100,000	$ 300,000