Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

The components of income before income taxes for the years ended December 31, 2015, 2014 and 2013 were as follows (dollars in thousands):

	2015		2014		2013
United States	$	236,613	$	276,343	$	211,094
Foreign	64,318		91,519		106,498
Total	$	300,931	$	367,862	$	317,592

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

The components of the provision for income taxes for the years ended December 31, 2015, 2014 and 2013 were as follows (dollars in thousands):

	2015			2014		2013
United States:
Current
Federal	$	12,003		$	15,647	$	6,571
State	8,181			7,134		6,031
Deferred
Federal	41,975			49,799		62
State	5,383			8,727		4,890
	67,542			81,307		17,554
Foreign:
Current	11,031			17,591		22,697
Deferred	(2,679		)	8,209		6,045
	8,352			25,800		28,742
Total	$	75,894		$	107,107	$	46,296

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

The following is a summary of the effective tax rate reconciliation for the years ended December 31, 2015, 2014 and 2013:

	2015		2014		2013
Tax provision at statutory rate	35.0	%	35.0	%	35.0	%
Effect of foreign operations	(1.7	)%	(1.7	)%	(2.1	)%
Effect of foreign rate change	(3.3	)%	—	%	—	%
State income taxes, net of federal income tax benefit	3.0	%	2.8	%	2.2	%
Benefit of track maintenance credit	(9.1	)%	(7.3	)%	(21.0	)%
Other, net	1.3	%	0.3	%	0.4	%
Effective income tax rate	25.2	%	29.1	%	14.5	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

The components of net deferred income taxes as of December 31, 2015 and 2014 were as follows (dollars in thousands):

	2015			2014
Deferred tax assets:
Track maintenance credit	$	237,411		$	227,102
Net operating loss carryforwards	20,810			16,008
Accruals and reserves not deducted for tax purposes until paid	14,896			11,027
Stock-based compensation	9,253			6,954
Deferred revenue	5,736			3,652
Deferred compensation	3,454			2,810
Foreign tax credit	—			1,964
Nonshareholder contributions	2,150			1,871
Interest rate swaps	4,223			1,664
Alternative minimum tax credit	1,592			1,592
Pension and postretirement benefits	15,411			425
Other	752			457
	315,688			275,526
Valuation allowance	(19,315		)	(14,793		)
Deferred tax liabilities:
Property and intangible basis difference	(1,270,901		)	(1,088,572		)
Other	(6,338		)	(1,519		)
Net deferred tax liabilities	$	(980,866	)	$	(829,358	)

Summary of Valuation Allowance [Table Text Block]

A reconciliation of the beginning and ending amount of the Company's valuation allowance is as follows (dollars in thousands):

	2015
Balance at beginning of year	$	14,793
Increase for state net operating losses	89
Increase for foreign net operating losses	6,397
Decrease for expiration of foreign tax credit	(1,964		)
Balance at end of year	$	19,315

Summary of Income Tax Contingencies [Table Text Block]

A reconciliation of the beginning and ending amount of the Company's liability for uncertain tax positions is as follows (dollars in thousands):

	2015			2014		2013
Balance at beginning of year	$	4,324		$	3,155	$	3,155
Increase for tax positions related to prior years	—			1,169		—
Decrease for effects of foreign exchange rates	(127		)	—		—
Balance at end of year	$	4,197		$	4,324	$	3,155

Summary of Income Tax Examinations [Table Text Block]

As of December 31, 2015, the following tax years remain open to examination by the major taxing jurisdictions to which the Company is subject:

	Open Tax Years
Jurisdiction	From		To
United States	2002	-	2015
Australia	2010	-	2015
Belgium	2013	-	2015
Canada	2010	-	2015
Germany	2010	-	2015
Mexico	2008	-	2015
Netherlands	2010	-	2015
Poland	2010	-	2015
U.K.	2009	-	2015