Qualified Employee Benefit Plans - Additional Information (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) investment	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined contribution expense for foreign entities	$ 6,800,000	$ 7,900,000	$ 7,300,000
Estimated employer contributions in 2017	4,000,000
Other comprehensive (loss) gain	(2,972,000)	2,207,000	(24,555,000)
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to qualified profit sharing plan	14,300,000	14,200,000	13,500,000
Other comprehensive (loss) gain	(3,032,000)	1,888,000	(20,571,000)
Earnings of plan assets exceeding expectations	1,800,000	5,300,000
Discount rate and lump sum interest rates	3,500,000	5,600,000	12,000,000
Mortality assumption	$ 1,700,000	1,400,000	$ 7,500,000
Defined benefit plan, amortization period	36 years
Future amortization of prior service cost	$ 23,959
Loss to be amortized over next fiscal year	1,100,000
Accumulated benefit obligation	$ 111,300,000	$ 107,800,000
Assumptions used calculating benefit obligation, discount rate, percent	4.55%	4.75%
Expected long-term rate of return on plan assets	6.50%	7.00%	7.50%
Return Seeking Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum, percent	30.00%
Target plan asset allocations range maximum, percent	60.00%
Target plan asset allocations, percent	40.00%
Risk Mitigating Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum, percent	10.00%
Target plan asset allocations range maximum, percent	30.00%
Target plan asset allocations, percent	15.00%
Diversifying Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum, percent	0.00%
Target plan asset allocations range maximum, percent	25.00%
Target plan asset allocations, percent	17.00%
Dynamic Asset Allocation [Member]
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum, percent	18.00%
Target plan asset allocations range maximum, percent	38.00%
Target plan asset allocations, percent	28.00%
Fixed Income Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Retirement plan, number of investments | investment	2
Equity Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Retirement plan, number of investments | investment	3
Private Investment Trusts Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Retirement plan, number of investments | investment	2