Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2016 USD ($)
Goodwill [Line Items]
Highest goodwill balance among other reporting units			$ 5,675
Average goodwill balance among other reporting units			$ 836
Number of reporting units with allocated goodwill balances			222
Goodwill [Roll Forward]
Balance, beginning of period	$ 182,027	$ 183,190
Acquired goodwill	12,696	1,149
Goodwill, Translation Adjustments	(49)	(2,312)
Balance, end of period	194,674	182,027
Accumulated goodwill impairment losses	(9,266)	(9,266)
Goodwill impairment	(613)	0
Accumulated goodwill impairment losses	(9,879)	(9,266)
Goodwill	$ 184,795	$ 172,761