Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Taxes [Abstract]

Summary of Income Before Taxes

	Year Ended December 31,
(in thousands)	2017		2016		2015
United States operations	$	135,177	$	128,072	$	69,822
Foreign operations		18,798		21,043		4,017
Total	$	153,975	$	149,115	$	73,839

Provision for Income Taxes

	Year Ended December 31,
(in thousands)	2017		2016		2015
Current expense:
Federal	$	12,329	$	43,850	$	5,465
State		6,763		13,039		(362)
Foreign		3,435		6,573		1,126
Total current		22,527		63,462		6,229
Deferred (benefit) expense:
Federal		(30,021)		(3,054)		19,583
State		5,560		(5,302)		2,735
Foreign		1,365		(1,813)		—
Total deferred		(23,096)		(10,169)		22,318
Total (benefit) provision	$	(569)	$	53,293	$	28,547

Reconciliation of Provision for Income Taxes

	Year Ended December 31,
	2017				2016				2015
(dollars in thousands)	Amount		Rate		Amount		Rate		Amount		Rate
Federal income tax expense at statutory tax rate	$	53,892	35.0	%	$	52,190	35.0	%	$	25,844	35.0	%
State income taxes, net of federal tax benefit		7,753	5.0			4,614	3.1			3,685	5.0
Impact of federal tax law change		(53,348)	(34.6)			—	—			—	—
Officers' compensation		2,622	1.7			3,807	2.6			2,900	3.9
Domestic production activities deduction		(2,668)	(1.7)			(4,018)	(2.7)			(1,499)	(2.0)
Noncontrolling interest		(2,137)	(1.4)			—	—			—	—
Reversal of taxes payable due to statute expiration		(4,337)	(2.8)			—	—			—	—
Other		(2,346)	(1.6)			(3,300)	(2.3)			(2,383)	(3.2)
Income tax (benefit) provision	$	(569)	(0.4)	%	$	53,293	35.7	%	$	28,547	38.7	%

Significant Components of Deferred Tax Assets and Liabilities

The following is a summary of the significant components of the deferred tax assets and liabilities:

	As of December 31,
(in thousands)	2017		2016
Deferred tax assets:
Timing of expense recognition	$	22,730	$	36,055
Net operating losses		8,590		10,140
Other, net		15,618		33,507
Deferred tax assets		46,938		79,702
Valuation allowance		(381)		(460)
Net deferred tax assets		46,557		79,242
Deferred tax liabilities:
Intangible assets, due primarily to purchase accounting		(30,019)		(34,679)
Fixed assets, due primarily to purchase accounting		(73,833)		(107,081)
Construction contract accounting		(17,539)		(12,564)
Joint ventures		(11,343)		(29,609)
Other		(22,263)		(24,970)
Deferred tax liabilities		(154,997)		(208,903)
Net deferred tax liabilities	$	(108,440)	$	(129,661)

Thenetdeferredtaxliabilitiesare presented intheConsolidatedBalanceSheetsas  follows:

	As of December 31,
(in thousands)	2017		2016
Deferred tax assets	$	64	$	1,346
Deferred tax liabilities		(108,504)		(131,007)
Net deferred tax liabilities	$	(108,440)	$	(129,661)

Reconciliation of Gross Unrecognized Tax Benefit

	As of December 31,
(in thousands)	2017		2016		2015
Beginning balance	$	7,574	$	3,612	$	7,636
Change in tax positions of prior years		(1,207)		3,543		(3,073)
Change in tax positions of current year		128		419		169
Reduction in tax positions for statute expirations		—		—		(1,120)
Ending Balance	$	6,495	$	7,574	$	3,612