Lease Commitments - Supplemental Balance Sheet and Cash Flow Information Related to Operating Leases (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating lease right-of-use assets	$ 27,036
Operating lease liabilities	31,141
Cash paid for amounts included in the measurement of operating lease liabilities	2,981
Right-of-use assets obtained in exchange for new operating lease obligations	$ 0
Weighted average remaining lease term for operating leases	9 years
Weighted average discount rate for operating leases	4.70%