Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net income	$ 25,140	$ 35,343	$ 40,182
Adjustments to reconcile net income to net cash flows:
Depreciation	21,604	21,559	23,118
Amortization of intangible assets	8,294	8,562	9,019
Amortization of deferred financing costs	802	1,366	927
Loss(Gain) on foreign currency, net	259	(395)	(157)
Amortization of inventory fair value adjustment			2,376
Accretion of debt discount, net	4,005	3,694	3,407
Loss on disposals and impairments	8,273	2,003	(92)
Loss on extinguishment of debt	1,989
(Benefit) provision for deferred taxes	(2,850)	(170)	2,712
Stock based compensation	4,230	4,004	3,101
Changes in assets and liabilities:
Trade receivables	(4,140)	7,223	(1,050)
Inventories	2,324	6,049	5,402
Accounts payable and accrued liabilities	4,333	2,816	(6,055)
Other current assets and liabilities	529	(3,343)	860
Other operating assets and liabilities	1,849	(1,895)	749
Net cash provided by operating activities	76,641	86,816	84,499
Cash flows from investing activities
Purchase of property, plant and equipment	(18,941)	(22,906)	(28,050)
Proceeds from sale of property		1,201	848
Acquisition of Stromag and Guardian businesses, net of cash acquired	(187,967)		(15,092)
Net cash used in investing activities	(206,908)	(21,705)	(42,294)
Cash flows from financing activities
Payment of debt issuance costs	(650)	(1,006)
Payments on term loan facility		(130,063)	(23,247)
Payments on Revolving Credit Facility	(31,861)	(14,998)	(9,190)
Dividend payments	(11,667)	(14,928)	(15,033)
Borrowing under Revolving Credit Facility	200,579	120,036	8,000
Payments of equipment, working capital notes, mortgages and other debt	(3,308)	(3,864)	(2,236)
Proceeds from equipment, working capital notes, mortgages and other debt	2,729	8,398	6,517
Shares surrendered for tax withholding	(1,337)	(1,182)	(1,158)
Purchase of non-controlling interest in Lamiflex		(878)
Purchases of common stock under share repurchase program	(4,713)	(17,298)	(17,618)
Net cash provided by financing activities	149,772	(55,783)	(53,965)
Effect of exchange rate changes on cash and cash equivalents	(707)	(6,511)	(4,341)
Net change in cash and cash equivalents	18,798	2,817	(16,101)
Cash and cash equivalents at beginning of year	50,320	47,503	63,604
Cash and cash equivalents at end of period	69,118	50,320	47,503
Cash paid during the period for:
Interest	7,161	7,237	7,618
Income taxes	10,855	15,729	31,631
Non-cash Financing and Investing:
Acquisition of property, plant and equipment included in accounts payable	459	$ 1,129	1,642
Conversion of convertible senior notes to common stock	$ 45,286
Acquisition of property, plant and equipment through capital leases			$ 539