Business Acquisitions (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Oct. 12, 2016	Dec. 31, 2015	Apr. 15, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 206,659		$ 115,452		$ 72,429
Downstream [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		$ 6,603
Accounts receivable		28,128
Unbilled receivable		10,786
Inventory		18,701
Prepaid and other current assets		4,380
Property, plant and equipment		20,869
Identifiable intangible assets		101,600
Accounts payable		(11,655)
Accrued and other expenses		(8,482)
Deferred revenue		(3,997)
Deferred income taxes		(42,660)
Total identifiable net assets		124,273
Goodwill		93,228
Total purchase price		$ 217,501
Schroedahl [Member]
Business Acquisition [Line Items]
Cash and cash equivalents				$ 36,316
Other current assets				11,470
Property, plant and equipment				1,999
Identifiable intangible assets				32,829
Current liabilities				(5,452)
Deferred income taxes				(7,285)
Other non-current liabilities				(642)
Total identifiable net assets				69,235
Goodwill				46,818
Total purchase price				$ 116,053