Acquisitions (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 29, 2016	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Business Acquisition [Line Items]
Real estate, furniture and equipment			$ 7,042
Goodwill			178,945	$ 144,513
Intangible Assets			32,395
Other assets			9,862
Other liabilities assumed			(2,251)
Worldwide Supplier of After-market (OEM) Parts [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	85.00%				89.50%
Business acquisition, cost of acquired entity, cash paid	$ 42,300	$ 73,300
London Acquisition, Inactive insurance Company, and Worldwide Supplier of After-market (OEM) Parts [Member]
Business Acquisition [Line Items]
Cash and cash equivalents			2,721
Non controlling interest			(5,000)
Assets, Total [Member]
Business Acquisition [Line Items]
Total assets acquired			80,542
Net Assets, Segment [Member]
Business Acquisition [Line Items]
Net assets acquired			73,291
Goodwill [Member]
Business Acquisition [Line Items]
Goodwill			$ 28,522