Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net Income	$ 40,001	$ 45,370	$ 50,572
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	34,873	33,053	19,686
Gain on sale of marketable equity securities	(347)		(107)
Other-than-temporary impairment of marketable securities	230
Loss (gain) on disposal of property and equipment	239	233	(117)
Amortization of debt issuance costs	648	693
Write-off of debt issuance costs	1,272
Stock-based compensation	494	1,485	585
Provision for doubtful accounts	3,004	3,504	1,515
Deferred income taxes	478	1,433	2,495
Change in assets and liabilities:
Trade and other accounts receivable	4,424	(19,857)	767
Prepaid income taxes, prepaid expenses and other assets	4,347	984	(3,594)
Accounts payable, accrued expenses, insurance and claims and other current liabilities	(11,695)	13,027	(15,152)
Due to/from affiliates, net	83	(1)	837
Other long-term liabilities	253	(532)	103
Net cash provided by operating activities	78,304	79,392	57,590
Cash flows from investing activities:
Capital expenditures	(26,257)	(59,784)	(17,035)
Proceeds from the sale of property and equipment	816	1,326	1,790
Purchases of marketable securities	(1,159)	(2,063)	(24)
Proceeds from sale of marketable securities	441		520
Acquisitions of businesses		(2,648)	(121,057)
Net cash used in investing activities	(26,159)	(63,169)	(135,806)
Cash flows from financing activities:
Proceeds from borrowing - revolving debt	172,758	134,228	48,218
Repayments of debt - revolving debt	(161,293)	(134,358)	(52,218)
Proceeds from borrowing - term debt	80,000	2,500	95,500
Repayments of debt - term debt	(120,000)	(4,572)
Repayments of debt - equipment facility	(55,428)
Proceeds from borrowing - equipment notes	83,578
Proceeds from borrowing - UBS facility		791
Repayments of debt - UBS facility		(791)
Dividends paid	(8,171)	(8,409)	(4,209)
Payment of capital lease obligations	(1,050)	(1,349)	(42)
Purchases of treasury stock	(35,065)	(5,631)	(6)
Payment of earnout obligations related to acquisitions			(24)
Capitalized financing costs	(1,499)		(1,230)
Net cash (used in) provided by financing activities	(46,170)	(17,591)	85,989
Effect of exchange rate changes on cash and cash equivalents	(1,046)	(854)	(104)
Net increase (decrease) in cash	4,929	(2,222)	7,669
Cash and cash equivalents – beginning of period	8,001	10,223	2,554
Cash and cash equivalents – ending of period	12,930	8,001	10,223
Supplemental cash flow information:
Cash paid for interest	7,649	7,379	3,595
Cash paid for income taxes	$ 21,541	20,833	31,236
Acquisition of businesses:
Fair value of assets acquired, net of cash		1,270	156,741
Liabilities assumed			(33,738)
Fair value of acquisition obligations			(2,196)
Payment of acquisition obligations		1,378	250
Net cash paid for acquisition of businesses		$ 2,648	$ 121,057