Equity - AOCI Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Changes in the balances of each component of AOCI
Balance at the beginning of the period	$ 594,595
Other comprehensive income (loss)	(99)	$ 89
Balance at the end of the period	665,016
Accumulated Other Comprehensive Income
Changes in the balances of each component of AOCI
Balance at the beginning of the period	1,777
Other comprehensive income (loss)	(99)
Balance at the end of the period	1,678
Foreign Currency Translation
Changes in the balances of each component of AOCI
Balance at the beginning of the period	1,797
Other comprehensive income (loss)	15
Balance at the end of the period	1,812
Unrealized Gains (Losses) on Available for Sale Securities
Changes in the balances of each component of AOCI
Balance at the beginning of the period	(20)
Other comprehensive income (loss)	(114)
Balance at the end of the period	$ (134)