Short-Term Borrowings (Details)			9 Months Ended
	Sep. 05, 2017 USD ($)	Sep. 19, 2016 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Line of Credit Facility [Line Items]
Borrowing formula, eligible accounts receivable			75.00%
Minimum trailing adjusted EBITDA			$ (1,500,000,000)						$ 0
Maximum add-back of restructuring costs in calculation of adjusted EBITDA			10,786,000,000
Outstanding balance			15,000,000							$ 25,000,000
Remaining borrowing capacity			19,400,000
Scenario, Forecast [Member]
Line of Credit Facility [Line Items]
Minimum trailing adjusted EBITDA				$ 2,000,000,000	$ 0	$ (5,000,000,000)		$ 3,000,000,000
Maximum add-back of restructuring costs in calculation of adjusted EBITDA				$ 2,000,000,000	$ 3,000,000,000	$ 11,000,000,000	$ 12,235,000,000	$ 10,471,000,000
Below Minimum Trailing Adjusted Earnings Before Interest, Taxes, Depreciation And Amortization [Member]
Line of Credit Facility [Line Items]
Minimum trailing adjusted EBITDA			8,000,000.0
Geographic Distribution, Foreign [Member] | Trade Accounts Receivable [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Borrowing formula, eligible accounts receivable		85.00%
Swingline Loan [Member] | 2016 Debt Agreement [Domain]
Line of Credit Facility [Line Items]
Current borrowing capacity		$ 10.0
Letter of Credit [Member] | 2016 Debt Agreement [Domain]
Line of Credit Facility [Line Items]
Current borrowing capacity		5.0
Line of Credit [Member] | 2016 Debt Agreement [Domain]
Line of Credit Facility [Line Items]
Current borrowing capacity		30.0
Maximum borrowing capacity		25.0
Borrowing base threshold			$ 2,500,000.0
Debt Instrument, Interest Rate, Increase (Decrease)	0.50%
Line Of Credit Facility, Debt Covenant, Interest Rate Increase, Minimum EBITDA In Two Consecutive Quarters	$ 0
Line Of Credit Facility, Debt Covenant, Interest Rate Increase, Minimum Capital Raised	$ 15,000,000.0
Annual administrative fee		25,000
Annual commitment fee		82,500
Loan origination fees		$ 400,000
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Month Ended 12/31/2017 [Member]
Line of Credit Facility [Line Items]
Minimum liquidity ratio		1.50
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Availability, 70 Percent Or More [Member]
Line of Credit Facility [Line Items]
Percentage of commitment fee on unused capacity		0.35%
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Availability, 30 Percent Or More And Less Than 70 Percent [Member]
Line of Credit Facility [Line Items]
Percentage of commitment fee on unused capacity		0.325%
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Availability, Below 30 Percent [Member]
Line of Credit Facility [Line Items]
Percentage of commitment fee on unused capacity		0.30%
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Month Ended 1/31/2018 And 2/28/2017 [Member]
Line of Credit Facility [Line Items]
Minimum liquidity ratio		1.35
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Month Ended 3/31/2018 [Member]
Line of Credit Facility [Line Items]
Minimum liquidity ratio		1.50
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Month Ended 4/30/2018 And 5/31/2018 [Member]
Line of Credit Facility [Line Items]
Minimum liquidity ratio		1.35
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Month Ended 6/30/2018 And Thereafter [Member]
Line of Credit Facility [Line Items]
Minimum liquidity ratio		1.50
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Prime Rate [Member] | Availability, 70 Percent Or More [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate		0.75%	0.25%
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Prime Rate [Member] | Availability, 30 Percent Or More And Less Than 70 Percent [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate		1.00%	0.50%
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Prime Rate [Member] | Availability, Below 30 Percent [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate		1.25%	0.75%
Line of Credit [Member] | 2016 Debt Agreement [Domain] | Geographic Distribution, Domestic [Member] | Trade Accounts Receivable [Member]
Line of Credit Facility [Line Items]
Borrowing formula, eligible accounts receivable		85.00%