Leases (Maturities of Operating Lease Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
2019 (remainder of year)	$ 12,308
2020	17,414
2021	14,821
2022	11,175
2023	7,705
Thereafter	37,722
Total lease payments	101,145
Less imputed interest	(18,258)
Total	82,887
Current operating lease liabilities, included in accrued liabilities	13,932		$ 0
Long-term operating lease liabilities	$ 68,955	$ 68,939	$ 0
Weighted average remaining lease term - operating leases	10 years 10 months 24 days
Weighted average discount rate - operating leases	3.70%