Goodwill and Intangible Assets, Goodwill) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)
Goodwill and Intangible Assets [Abstract]
Balance at beginning of period	$ 275,205
Preliminary purchase price allocations for acquisitions (Note 7)	5,836
Effect of foreign currency translation adjustments	200
Balance at March 31, 2017	$ 281,241