Other Intangible Asset - Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other intangible assets
Amortizable intangibles, gross carrying amount	$ 198,075	$ 198,075
Amortizable intangibles, accumulated amortization	100,997	89,525
Finite-Lived Intangible Assets, Net, Total	97,078	108,550
Intangible Assets, Gross (Excluding Goodwill), Total	275,675	275,675
Net Carrying Amount	174,678	186,150
Dealer network
Other intangible assets
Amortizable intangibles, gross carrying amount	80,000	80,000
Amortizable intangibles, accumulated amortization	59,000	55,000
Finite-Lived Intangible Assets, Net, Total	21,000	25,000
Customer relations
Other intangible assets
Amortizable intangibles, gross carrying amount	80,920	80,920
Amortizable intangibles, accumulated amortization	16,607	11,304
Finite-Lived Intangible Assets, Net, Total	64,313	69,616
Patents
Other intangible assets
Amortizable intangibles, gross carrying amount	21,136	21,136
Amortizable intangibles, accumulated amortization	11,974	10,721
Finite-Lived Intangible Assets, Net, Total	9,162	10,415
Noncompete agreements
Other intangible assets
Amortizable intangibles, gross carrying amount	8,640	8,640
Amortizable intangibles, accumulated amortization	7,877	7,055
Finite-Lived Intangible Assets, Net, Total	763	1,585
Trademark
Other intangible assets
Amortizable intangibles, gross carrying amount	5,459	5,459
Amortizable intangibles, accumulated amortization	3,619	3,525
Finite-Lived Intangible Assets, Net, Total	1,840	1,934
Backlog
Other intangible assets
Amortizable intangibles, gross carrying amount	1,900	1,900
Amortizable intangibles, accumulated amortization	1,900	1,900
License
Other intangible assets
Amortizable intangibles, gross carrying amount	20	20
Amortizable intangibles, accumulated amortization	20	20
Trademark and tradenames
Other intangible assets
Indefinite-lived intangibles, net carrying amount	$ 77,600	$ 77,600