Long-Term Debt and Credit Arrangements - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions		9 Months Ended		12 Months Ended
	Jun. 14, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Aug. 15, 2018	May 31, 2018
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in the Remainder of 2018		$ 111,400,000
Long-term Debt, Maturities, Repayments of Principal in 2019		47,500,000
Long-term Debt, Maturities, Repayments of Principal in 2020		7,500,000
Long-term Debt, Maturities, Repayments of Principal in 2021		7,500,000
Long-term Debt, Maturities, Repayments of Principal in 2022		7,500,000
Long-term Debt, Maturities, Repayments of Principal , thereafter		253,300,000
Total long-term debt		316,926,000	$ 225,922,000	$ 178,453,000
Current maturities of long-term debt		116,796,000	14,796,000	46,048,000
Line of credit facility, maximum borrowing capacity		500,000,000
Line of Credit Facility, Current Borrowing Capacity		300,000,000
Line of Credit, Current		148,100,000
Line of Credit, minimum cash balance		150,000,000
Line of Credit Facility, Increase (Decrease), Net		100,000,000
Letters of Credit Outstanding, Amount		30,600,000
Proceeds from long-term debt		$ 143,250,000	0
Consolidated Leverage Ratio, Maximum		3.00
Consolidated Interest Coverage Ratio, Actual		18.83
Consolidated Interest Coverage Ratio, Covenant		4.00
Layne Christensen Company [Member]
Debt Instrument [Line Items]
Acquisition purchase price	$ 349,840,000
Minimum [Member]
Debt Instrument [Line Items]
Consolidated leverage ratio financial covenant		3.00
Acquisition purchase price		$ 100,000,000
Maximum [Member]
Debt Instrument [Line Items]
Consolidated leverage ratio financial covenant		3.50
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 200,000,000
Line of Credit Facility, Remaining Borrowing Capacity		350,000,000
Proceeds from long-term debt		137,000,000	30,000,000	55,000,000
Term Loan [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt		7,500,000	5,000,000	6,200,000
Line of Credit, Current		148,100,000
Long-term debt		$ 140,600,000	86,300,000	83,800,000
Debt instrument redemption price percentage		1.25%
8.0 % Convertible Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		8.00%
8.0 % Convertible Notes [Member] | Layne Christensen Company [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	8.00%	8.00%
Debt instrument, fair value	$ 121,600,000
Debt instrument frequency of periodic payment		convertible notes that have an interest rate of 8.0% per annum, payable semi-annually on May 1 and November 1 (“8.0% Convertible Notes”).
Debt instrument maturity, Ending date	Aug. 15, 2018
Debt Instrument, maturity date, description		The 8.0% Convertible Notes had a maturity date of August 15, 2018 (Maturity Date).
Debt instrument, extended maturity date	Aug. 15, 2018
Debt instrument, convertable note		$ 52,000,000
Debt instrument, remaining fair value					$ 38,900,000
Debt instrument, accrued interest					$ 900,000
Additional paid-in capital		$ 30,700,000
8.0 % Convertible Notes [Member] | Layne Christensen Company [Member] | Common Stock [Member]
Debt Instrument [Line Items]
Debt instrument, convertible shares		1.2
Senior Notes [Member] | 2019 Notes [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 80,000,000	120,000,000	80,000,000
Debt instrument, interest rate, stated percentage		6.11%
Total long-term debt		$ 40,000,000	110,000,000	$ 40,000,000
Current maturities of long-term debt		40,000,000	10,000,000
Senior Notes [Member] | 2019 Notes [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in the Remainder of 2018		0	$ 30,000,000
Line of Credit [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity		$ 182,400,000
Consolidated leverage ratio financial covenant		1.74
Debt Instrument, Basis Spread on Variable Rate, LIBOR Loans		1.50%
Debt Instrument, Basis Spread on Variable Rate		1.50%
Derivative, Variable Interest Rate						2.76%
Consolidated Fixed Charge Coverage Ratio, Minimum, Collateral Release Period		1.25
Consolidated Leverage Ratio, Maximum, Collateral Release Period		2.50
Consolidated Tangible Net Worth, Actual		$ 1,100,000,000
Consolidated Tangible Net Worth, Covenant		$ 786,500,000
Line of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End		3.90%
Line of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End		5.75%
Convertible Notes [Member] | 4.25% Notes due 2018 [Member]
Debt Instrument [Line Items]
Common stock conversion rate		11.8360
Common stock conversion principal amount		$ 1,000
Conversion price per share		$ 84.49
Convertible Notes [Member] | 4.25% Notes due 2018 [Member] | Layne Christensen Company [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	4.25%
Current maturities of long-term debt		$ 69,900,000
Debt instrument, fair value	$ 69,900,000
Debt instrument frequency of periodic payment		convertible notes that have an interest rate of 4.25% per annum, payable semi-annually in arrears on May 15 and November 15 (“4.25% Convertible Notes”).
Debt instrument maturity, Beginning date		May 31, 2015
Debt instrument maturity, Ending date		Nov. 30, 2015
Debt instrument, extended maturity date		Nov. 30, 2015