Commitments and Contingencies Warranty Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Total warranty expense	$ 6,187	$ 5,901	$ 7,966	$ 10,763