Fair Value Measurement Financial Assets and Liabilities Accounted for at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments under executive deferred compensation plan	$ 28,715	$ 26,292
Private equity securities	32	26
Private equity securities measured at net asset value	4,890	7,195
Foreign currency forward contracts, assets	7,401	431
Obligations under executive deferred compensation plan	28,715	26,292
Foreign currency forward contracts, liabilities	3,613	0
Quoted Prices in Active Markets for Identical Items (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments under executive deferred compensation plan	28,715	26,292
Private equity securities	32	26
Private equity securities measured at net asset value	0
Foreign currency forward contracts, assets	0	0
Obligations under executive deferred compensation plan	28,715	26,292
Foreign currency forward contracts, liabilities	0
Quoted Prices in Active Markets for Similar Items (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments under executive deferred compensation plan	0	0
Private equity securities	0	0
Private equity securities measured at net asset value	0
Foreign currency forward contracts, assets	7,401	431
Obligations under executive deferred compensation plan	0	0
Foreign currency forward contracts, liabilities	3,613
Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments under executive deferred compensation plan	0	0
Private equity securities	0	0
Private equity securities measured at net asset value	0
Foreign currency forward contracts, assets	0	0
Obligations under executive deferred compensation plan	0	$ 0
Foreign currency forward contracts, liabilities	$ 0