Basis of Presentation (Tables)

6 Months Ended

Jun. 30, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]

These adjustments had no effect on previously reported results of operations or retained earnings. The following table provides a summary of the adjustments from amounts previously reported.

	Six Months Ended June 30, 2017
	As Previously Reported			Adjustments			As Adjusted
Cash flows from operating activities:
Changes in assets and liabilities:
Other Current Assets	5,562			(4,206		)	1,356
Restricted cash, cash equivalents and investments balance	(3,497		)	3,461			(36		)
Net cash provided by operating activities	70,788			(745		)	70,043
Cash flows from investing activities
Change in restricted cash, cash equivalents and investments balance	(5		)	5			—
Net cash used in investing activities	(19,621		)	5			(19,616		)
Net increase in cash, cash equivalents and restricted cash	$	12,256		$	(740	)	$	11,516
Cash, cash equivalents and restricted cash at the beginning of period	10,622			40,406			51,028
Cash, cash equivalents and restricted cash at the end of period	$	22,878		$	39,666		$	62,544

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the accompanying condensed consolidated balance sheets and related notes to the amounts presented in the accompanying condensed consolidated statements of cash flows.

	June 30, 2018			December 31, 2017
Cash and cash equivalents	$	22,894		$	15,147
Restricted cash and cash equivalents (included in other current assets)	24,550			25,506
Restricted cash, cash equivalents and investments	61,839			64,315
Total cash, cash equivalents and restricted cash and investments	109,283			104,968
Less restricted investments	(4,672		)	(6,074		)
Total cash, cash equivalents and restricted cash	$	104,611		$	98,894