Fair Value Measurements - Financial Assets and Liabilities, Recurring (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets
Deferred compensation plan	$ 17,080	$ 14,699
Derivative instruments	25,700	60,105
Liabilities
Deferred compensation plan	25,791	25,780
Recurring basis
Assets
Deferred compensation plan	17,080	14,699
Derivative instruments	25,700	60,105
Total assets	42,780	74,804
Liabilities
Deferred compensation plan	25,791	25,780
Derivative instruments	0	2,440
Total liabilities	25,791	28,220
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring basis
Assets
Deferred compensation plan	17,080	14,699
Derivative instruments	0	0
Total assets	17,080	14,699
Liabilities
Deferred compensation plan	25,791	25,780
Derivative instruments	0	0
Total liabilities	25,791	25,780
Significant Other Observable Inputs (Level 2) | Recurring basis
Assets
Deferred compensation plan	0	0
Derivative instruments	16,542	35,689
Total assets	16,542	35,689
Liabilities
Deferred compensation plan	0	0
Derivative instruments	0	0
Total liabilities	0	0
Significant Unobservable Inputs (Level 3) | Recurring basis
Assets
Deferred compensation plan	0	0
Derivative instruments	9,158	24,416
Total assets	9,158	24,416
Liabilities
Deferred compensation plan	0	0
Derivative instruments	0	2,440
Total liabilities	$ 0	$ 2,440