Lease Commitments (Summary of Lease Costs) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 22,750
Finance lease cost: Amortization of right-of-use asset	36
Finance lease cost: Interest on lease liability	64
Short-term lease cost	561
Variable lease cost	3,202
Sublease income	(598)
Total lease cost	26,015
Cash paid for amounts included in the measurement of operating lease liabilities	23,859
Cash paid for amounts included in the measurement of finance lease liabilities	60
Right-of-use asset obtained in exchange for new operating lease liabilities	9,396
Right-of-use asset obtained in exchange for new finance lease liabilities	$ 3,498
Weighted average remaining lease term - operating leases	13 months 6 days
Weighted average remaining lease term - finance leases	39 months 18 days
Weighted average discount rate - operating leases	4.09%
Weighted average discount rate - finance leases	4.43%