Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of unrecognized tax benefits
Balance at the beginning of the period	$ 1,307	$ 3,456	$ 3,843
Additions based on tax positions related to prior years	310	7	297
Reductions based on tax positions related to prior years	(514)	(1,146)	(494)
Additions for tax positions of the current year	191	165	837
Settlements	0	(680)	(435)
Lapse of statute of limitations	(187)	(495)	(592)
Balance at the end of the period	1,107	1,307	3,456
Portion of uncertain tax benefit, if recognized, would reduce effective tax rate	200	0	700
Decrease in accrued interest as a result of the reversal of accrued interest associated with the lapse of statutes of limitations	0	$ 200	300
Accrued interest	$ 200		$ 400